The British actress is set to play the titular nanny in the follow-up, titled Mary Poppins Returns, and now multiple reports suggest her The Devil Wears Prada co-star Streep will take on the role of her cousin Topsy.

If the Oscar winner signs on, it will mark the duo's third film together, after appearing in another Disney movie musical, Into The Woods. The director of the fairytale film, Rob Marshall, will also helm Mary Poppins Returns.

Hamilton creator and star Lin-Manuel Miranda has also been confirmed for the film, portraying a street lamplighter called Jack.

Mary Poppins Returns has a similar plotline set-up to the original 1964 fantasy film, which starred Julie Andrews as the Banks family's magical nanny and DICk Van Dyke as lovable chimney sweep Bert.

In the sequel, Mary and Jack partner up to help the Banks children, who are now full-grown adults, find magic in life again during Depression-era London.

Marc Shaiman is teaming up with Tony Award winner Scott Wittman to compose original songs and a score for Mary Poppins Returns.