After months of speculation, Disney confirmed in May that Emily Blunt and Hamilton creator/star Lin Manuel-Miranda have signed on to star in Disney's Mary Poppins Returns. The casting reunited Emily Blunt with her Into the Woods director Rob Marshall, and now it seems that another star from that musical has come aboard for this project. Oscar winner Meryl Streep is in talks to join the cast as Topsy, Mary Poppins' cousin.

Variety reports that Meryl Streep will be singing once again in this movie, much like her role as The Witch in Disney's Into the Woods, which landed the actress her record-breaking 19th Oscar nomination. Topsy is said to be a supporting role, and a character that wasn't featured in the original Mary Poppins movie that debuted in 1964. Topsy does appear in author P.L. Travers' subsequent books.

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Topsy Tartlet is introduced in P.L. Travers' 1935 novel Mary Poppins Comes Back, who becomes a cousin to Mary Poppins through marriage after Topsy marries Arthur Turvey, which changes her name to Topsy Turvey. No details have been given for her role in this movie, or how the character may be changed from the books to the movie. The screenplay will be written by Oscar nominee David Magee based on The Mary Poppins Stories by P.L. Travers, with Oscar nominee and Tony Award winner Marc Shaiman composing an all-new score and Shaiman and Emmy nominee and Tony Award winner Scott Wittman writing original songs for this Disney adaptation.

Blunt has been cast as Mary Poppins and Lin-Manuel Miranda will play a new character, a street lamplighter named Jack. Drawing from the wealth of material in P.L. Travers' seven additional novels, the story will take place in Depression-era London (when the books were originally written) and follows a now-grown Jane and Michael Banks, who, along with Michael's three children, are visited by the enigmatic Mary Poppins following a personal loss. Through her unique magical skills, and with the aid of her friend Jack, she helps the family rediscover the joy and wonder missing in their lives.

Disney has set a December 25, 2018 release date for Mary Poppins Returns, but we don't know when production will begin quite yet. As of now, the movie's only direct competition is an untitled Warner Bros.' "event film," with Sony releasing their animated Spider-Man movie on December 21, 2018. Meryl Streep will next be seen portraying the title character in Paramount's Florence Foster Jenkins, hitting theaters August 12.