One of the high points of WandaVision is the series gives a bigger role to what had been merely supporting characters in the MCU until now. Everyone from Wanda Maximoff to her android boyfriend Vision, to Jimmy Woo and Darcy Lewis, get to show fans what they have been up to in the background of the whole "Infinity War" saga.
The character of Monica Rambeau, played by Teyonah Parris, is one such person who first showed up as a tween in Captain Marvel, and is now a fully-grown secret agent working for SWORD in WandaVision. Fans have noticed that Monica, who idolized Carol Danvers aka Captain Marvel as a child, seems to have a strained relationship with the superheroine now. In an interview with ET Canada, Parris hinted at the source of the tension.
"Well, as you know, I was announced to be joining the cast of Captain Marvel 2 with Brie Larson's Captain Marvel and the Kamala Khan character. I do believe that we're going to get more into that relationship, and what's going on with those two... Not only did [Monica's mother] pass, but Monica wasn't there to help her mother transition. And that's a very hard pill to swallow. The guilt and the shame and whatever other grief she might be trying to sort through, while returning to work on a project she doesn't even typically do - there are parallels between Monica's grief and trauma and tragedy, as well as what Wanda is experiencing. Monica connects with Wanda on that level."
In WandaVision, we learn that Monica Rambeau was one of the characters who was blipped out of existence after Thanos' snap. When she returned five years later, she learned her mother Maria had succumbed to cancer in the intervening time period. It seems Monica might blame Captain Marvel for not helping her mother in her fight against the deadly disease, and in some ways holds Carol responsible for Maria's demise.
This would explain why Monica has not even attempted to get Captain Marvel's help in dealing with Wanda, even though it is becoming increasingly clear that the latter is an immensely powerful threat who can only be stopped by someone like Carol. Parris goes on to state that the relationship between Monica and Captain Marvel will have to be resolved in Captain Marvel 2, while WandaVision will continue to deal with the fallout of the warping of reality in the town of Westview.
"We do have a lot of real estate and time to play with the relationships between Carol and Monica [in Captain Marvel 2]... There's still a lot more story to be told [in the show's final three episodes]."
Written by Jac Schaeffer and directed by Matt Shakman, WandaVision stars Elizabeth Olsen as Wanda Maximoff/Scarlet Witch, Paul Bettany as Vision, Randall Park as Agent Jimmy Woo, Kat Dennings as Darcy Lewis, Teyonah Parris as Monica Rambeau, and Kathryn Hahn as Agnes. New episodes air Fridays on Disney+.