When Amy Duncan returns to work as a nurse, she tells her family to stay at home, but is obviously worried about her husband Bob's ability to take care of their baby daughter Charlie. Bob assures her everything will be fine at home, and her teenage daughter Teddy, whose study date at the library is canceled because of this, goes against Amy's wishes and invites her date Spencer (Shane Harper) to come to their house. Teddy gets distracted by him, and they repeatedly try to kiss, but the Duncan family members keep interrupting. Her older brother PJ is trying to have a jam session with his best friend Emmett (Micah Williams) and her younger brother Gabe is feeling as if everyone is forgetting about him and goes to Mrs. Dabney's (Patricia Belcher) house to eat her food. Meanwhile, Bob slips and falls down the stairs with Charlie in his arms, who he catches when he reaches the bottom and Teddy has to take care of Charlie while PJ drives Bob to the hospital.
PJ takes Charlie to the park and accidentally swaps strollers with a girl named Emma (Gilland Jones), and brings home the wrong baby. Teddy, PJ, and Gabe search everywhere and they come to the point where they have to tell Amy and Bob. Elsewhere, Amy and Bob go on a date to a Mexican Restaurant to get their minds off of Charlie, but when Emma shows up at the restaurant that Bob and Amy are at, the Duncan kids sneak in to switch infants.
PJ and Gabe suspect that their neighbor Mrs. Dabney has killed her husband, Mr. Dabney, and they try to find evidence to prove it, while babysitting Charlie. Meanwhile, Teddy becomes jealous that her best friend, Ivy (Raven Goodwin) has become texting buddies with Amy, which Teddy thinks is lame, so she decides to spend time with Ivy's mother, Mary Lou Wentz (Ellia English) who is unexciting and is very boring, so Teddy learns that Amy is not as lame as she originally thought.
Amy convinces Teddy to audition to be the school's unlucky ram mascot Whammy, due to Amy being Whammy when she was Teddy's age. Teddy doesn't want to be Whammy, so she tries to throw the tryout, consequently it turns out she was the only one who tried out, so Teddy becomes the Whammy. Her mother is excited, but when Teddy reveals she never wanted to be Whammy in a huge outburst, Amy is dismayed and decides to fill in for Teddy at the game, but when rival school North High kidnaps Amy, thinking she was Teddy, she attacks them and goes back to the game, where Teddy is being attacked by North High's Viking mascot. Amy attacks the viking and she and Teddy take down the viking. Meanwhile, PJ worries that he is going bald like Bob; later, he challenges Emmett to a baby race with his nephew Mason against Charlie. Mason was ahead, but Charlie wins the race and takes her first steps while doing so.
A moonlight dance is approaching at Teddy's school. Teddy asks Spencer out for the big night and Ivy asks out Emmett, so she and Teddy can get rides to the dance. Teddy tries to get her first kiss from Spencer, but Emmett, who also likes Teddy, tries to distract Spencer which leads to a dance-off between the two. However, Teddy gets her first kiss with Spencer anyway. Meanwhile, Gabe tries to get his parents to argue at a parent-teacher meeting because he has been lying to his teacher and saying that he could not complete his assignments because of his parents arguing, so he releases the class' pet rat, which runs around the room scaring everyone.
When Teddy is supposed to be watching Gabe and Charlie, they make a huge mess in the kitchen. Amy prohibits Teddy to go a party she was invited to and Gabe is not allowed to use any kind of electronics for the rest of the day. Meanwhile, Teddy goes to the store, Gabe tags along. At the store, Charlie steals a pair of sunglasses at a grocery store. The rude owner Hugo, (Larry Joe Campbell), "arrests" her. Teddy and Gabe are in desperate need to leave. Teddy befriends Alice, (Hayley Holmes), a grocery store employee who gets fired after helping them escape. Back the Duncan residence, PJ and Emmett try to create a jingle for Bob's extermination business.
Bob gives Teddy and PJ new cell phones. Teddy tries to fool Amy into thinking that she is a "cool mom" by hanging with her to attend a midnight screening of Dusk (a parody of Twilight). But when she accidentally butt-dials her mother and says the whole thing, Amy and Ivy's mother get revenge by embarrassing Teddy and Ivy at the premiere. Later, the girls apologize. Meanwhile, PJ is stuck doing a science project with Van Brundt, the school bully, but PJ accidentally butt-dials him a voicemail scorning him. Gabe gets a new remote control helicopter, and tries to get rid of Charlie's new singing stuffed horse, although fails to do so.
It's Charlie's 1st birthday and the special day brings back crazy memories on the day she was born, including Bob and PJ's fishing trip which leads to a bear sleeping in their van so they are forced to steal a couple's (Diane Delano and Darenn Suttles) motorcycles. Teddy and Ivy's play about people overcoming differences and coming together and Amy in labor going to the hospital to deliver the baby. Gabe is home alone due to his family forgetting about him, but Mrs. Dabney catches him and takes him to the hospital anyway. Towards the end of the crazy day of Charlie's birth, the Duncans have a new sister and take a family picture. After the big story of the day Charlie was born, Mad Dog and Francis make a surprise visit to the Duncans with a motorcycle jacket for Charlie and Amy accepts them and they are now Charlie's godparents.
Bob makes a deal with Mrs. Dabney that if he chops down their tree that blocks her sunlight, she will keep her barking dog in her house. The tree, which houses PJ and Teddy's childhood treehouse, has sentimental value, so they stage a sit-in protest to prevent it from getting chopped down, because they want Charlie to experience it. Gabe and Amy join the strike, but Bob wants Mrs. Dabney's yapping dog to shut up. They all whind up in the tree house and it fell to the ground. However, when Mrs. Dabney reveals the dog isn't hers and she's just watching it for a neighbor, the Duncans launch a water balloon at her. In the end, Bob, PJ, and Gabe build a new tree house.
Teddy finds out that she has a great-uncle named Mel (Blake Clark) on her father's side but also learns that they don't speak to each other any more. So she and Ivy go to meet Uncle Mel to find out what happened. After they meet she learns that he loves baseball. He convinces Teddy to sneak him out of the nursing home. When they go to a baseball game, Teddy learns that Uncle Mel loves baseball a little too much when he causes quite a ruckus, including after he moons the team on the JumboTron and the police get involved. Meanwhile PJ and Gabe meet a photographer who offered to pay them $100 to use Charlie as a baby model and do it behind Amy's back after she says no.
When PJ meets a cute girl, Madison (Molly Burnett), at his new job at Kwikki Chikki, Emmett becomes upset that PJ is always putting his girlfriend before their activities. Coincidentally, Amy learns that Bob used to date Madison's mother Katherine. Meanwhile, Teddy spots that Gabe is getting picked on at school by a girl named Jo (G. Hannelius).
Gabe gets his first crush on a girl named Kit (Ryan Newman), he then lies to her by saying he is an only child so they can have something in common. Meanwhile, Mrs. Dabney asks Teddy to cat-sit her cat Kaboodle and Teddy thinks the cat is sick because he is just lying around. PJ uses Charlie to make more money on deliveries by saying he is watching her while his mother is in the hospital, not mentioning she actually works there.
Teddy tries warming up to her English teacher Mr. Dingwall (Patrick Bristow) by having Charlie take part in her oral presentation on the book Animal Farm after seeing him take a liking to her, but when Charlie vomits on the English teacher, the plan goes downhill. Meanwhile, Gabe and his basketball team fire Bob as their coach and hire Amy instead, after winning their first game under her guidance, but soon realize their mistake. Also, PJ begins to spend way too much time with Amy's friends.
Teddy accidentally puts Charlie's blanket in the donation pile instead of the laundry pile. She goes to look for it at the thrift shop but gets locked in the back of the donation truck. Meanwhile, PJ take Teddy's advice and plans a Moroccan feast for their parents' wedding anniversary. To celebrate their anniversary, Gabe, Amy and Bob go to the movie, but Charlie wrecks the feast by starting a one-baby food fight.
After PJ creates a funny video of Charlie, he posts it on the internet; the video becomes an instant worldwide sensation. Since the "Farty Charlie" is so popular, the Duncans are interviewed live on TV. Meanwhile, Teddy meets Spencer's parents, Paul and Linda (Maurice Godin and Stacey Travis). Teddy is impressed by their sophistication and peaceful lifestyle in comparison to the Duncans' loud and messy home. Paul and Linda watch the Duncan interview on TV, unbeknownst that they are Teddy's family, and insult them. Teddy reveals to them that that is her family and she has been hanging out at their house pretending to be apart of the Walsh family, but Teddy finally accepts that she is Duncan, and for that, she is proud of.
Spencer decides to help Teddy with her dance routine for the school talent show, but when he realizes she is terrible he fakes an injury to get out of it. When she finds out, she is upset, and breaks up with him. Meanwhile, Jo convinces Gabe that she will help him win the class president election but instead she purposely sabotages him and runs for election herself.
Teddy needs money for a new cell phone and gets a job as the neighborhood dog walker, but the job is less than glamorous. PJ gives Mitch (David Arnott), his boss at Kwikki Chikki, an idea for a new spokesmodel to bring in more customers, but when he expects Mitch to give the job to him, he makes Teddy the new spokesmodel after she walks into the restaurant. Teddy then comes up with a plan to get herself fired in order to give her brother the spotlight he deserves. Meanwhile, Amy sings a song with Charlie at her daycare and gets very competitive with the other mothers. Gabe uses a mouse to play a trick on Bob.
Gabe is left in charge of Charlie while doing a school assignment with Jo. Meanwhile, Teddy and Emmett trick PJ into going to the dentist and Amy agrees to help Bob on an extermination, when he actually promised to take her on a spa getaway.
Gabe and his friends have a sleepover and when they stay up and watch a scary movie, they later have trouble sleeping. Meanwhile, Charlie refuses to sleep in her new big girl bed, so she starts acting up on the day Teddy has an audition for a school play. PJ has dreams of what can happen if he becomes too fat.
Charlie bites Spencer because she suspects something is going on with him. Teddy is worried Charlie's biting will put their relationship in a crisis, but it is proved that Charlie's hunch is right when she meets Spencer with another girl Skyler (Samantha Boscarino). Teddy breaks up with Spencer and is heartbroken. Meanwhile, Gabe takes advantage of PJ by tricking him into signing a contract that says he has to drive Gabe wherever he wants to go. To get back at him, Amy pretends to be a ghost that haunts the car when Gabe sits in it.
After Teddy's break-up with Spencer, she and Skyler meet up to make a song, dissing Spencer, to post online. Spencer tells Teddy he regrets what he did and wants to start over. Meanwhile, Gabe and PJ are tired of sharing their room, so Gabe stays in Mrs. Dabney's house. Amy takes advantage of a gym which offers free daycare, so she can go to the spa, across the street.
A new kid on the block named Austin (Nathan Gamble) who Gabe is forced to become friends with develops a crush on Teddy. She uses the crush to her advantage to make Spencer jealous, who has already gotten a new girlfriend. Meanwhile, Bob temporarily fills in as a member of PJ and Emmett's band after Charlie gets their newest member, Jimmy (Ryan Heinke) sick.
Gabe accuses Charlie of leaving the garage door open and allowing his bike to be stolen when it is really just a scheme to get his father to buy him a new bike. Teddy films a play for her drama class (a special day in their life) and she picks the day she finds out that Amy was pregnant with Charlie, but she accidentally reveals to Amy how she really felt when she heard that a new baby was on the way. Meanwhile, Emmett gets a new girlfriend, Nina, from South America, and it seems she's crushing on PJ.
The Duncans go on a family road trip to a ski resort in the mountains. Teddy gets a reading from a psychic that she will meet the love of her life. Gabe abuses room service to get back at a bellhop (Steve Hytner) who used to be his teacher, PJ meets two sisters who take care of him after going on the wrong snowboarding trail. Bob and Amy find out they are not actually married because the judge who married them was a con artist.
Gabe has to pay off the room service and PJ owes some money to a kid named Walker (Davis Cleveland), whom he met on the ski lift, so they enter an ice skating contest. Teddy does not know who to pick of the three guys she meets, so asks Ivy to meet her at the lodge to help her decide. Spencer tries to win Teddy back, which results in him kissing Teddy on the ski lift. Amy and Bob struggle after Bob doesn't want to get married again while on vacation. Teddy tells Spencer she wants to just be friends, after Amy and Bob renew their vows.
After Bob tells Teddy that she is not ready to take her driving test, Teddy offers to drive Mrs. Dabney around town. She accepts her offer; they drive around town, helping Mrs. Dabney to complete her errands. At last, Teddy drives Mrs. Dabney to see her sister at the mountains. Eventually, they run out of gas and become stranded. Meanwhile, the Duncan's are preparing for Teddy's 16th birthday; PJ and Gabe have a hard time looking for a present for Teddy. In the end, Bob tells Teddy that he does not want her to drive because driving means leaving. When she leaves, she is never going to come back. Teddy and Bob share a moment and later reconcile. PJ and Gabe make up for not giving her a present by making a rap for her. The episode ends with Teddy earning her license; she is happy because she has the freedom to drive wherever she wants, but to her dismay, the entire family makes her go out to run errands.