The lyrics mention Emmeline Pankhurst, who with her daughters Christabel and Sylvia founded the Women's Social and Political Union in Manchester, England.
According to the songwriters in their autobiographical book, Walt's Time, actress Glynis Johns thought she was being offered the title role of "Mary Poppins" when in fact she had been signed to play "Mrs. Banks".
Thinking quickly, Disney softened Johns' disappointment of not getting the film's title role by telling her of the 'terrific new song' which the Sherman Brothers had written especially for her.
The Sherman Brothers deciphered Disney's coded hint, worked feverishly through their own lunch hour, and wrote "Sister Suffragette".
For instance, the original lyric: I'm Practically Perfect in every way In ev'rything I do and in everything I say Quickly evolved into: We're clearly soldiers in petticoats Dauntless crusaders for women's votes!