Meryl Streep is in talks to join Emily Blunt and Lin-Manuel Miranda in Mary Poppins Returns Walt Disney Pictures continues through the casting stage on it’s upcoming big screen sequel, Mary Poppins Returns. Already set to star Emily Blunt and Lin-Manuel Miranda, the feature is now looking at adding three-time Academy Award winner Meryl Streep. According to Variety, Streep would play Poppins’ cousin, Topsy.