Susan grips the handle of her parasol and doesn't tell Mary Poppins she used to ride on the backs of Gryphons. It's poor manners to one-up someone like that.. Umm, YES

Susan would be a marvelous assisstant for Mary Poppins, fixing other people's families because she never got to fix her own. And Mary can take some time off and do things Susan politely pretends to have no awareness of, and then they fix their hair and put on their smiles and go back to being fairy godmothers.