Mary Poppins is loosely based on something else.
Meryl Streep as Topsy, Mary Poppins's eccentric Eastern European cousin called Tatiana Antanasia Cositori Topotrepolovsky ("Topsy" for short) who runs a fix-it workshop in London
 On 14 September 2015, Walt Disney Pictures president Sean Bailey pitched a new Mary Poppins film to Rob Marshall, John DeLuca, and Marc Platt, as the team had produced Into the Woods for the studio the year prior

