The Newsroom actress Emily Mortimer has signed on to play a returning character for the Mary Poppins sequel.
Emily Mortimer, actress of the highly acclaimed HBO series The Newsroom, has joined the cast of Mary Poppins Returns. She’ll be playing the now grown-up Jane Banks, one of the two children that Mary Poppins looked after in the original movie.

In Depression-era London, a now-grown Jane and Michael Banks, 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.
Mortimer will join Emily Blunt who will play the title character, Meryl Streep who will play Topsy, Lin-Manuel Miranda who will play Jack the lamplighter, and Ben Whishaw who will be playing Jane’s younger brother, Michael Banks.
(Source)