Mrs. Brill is often referred to by George and Winifred Banks as Cook. The beginning of the film shows that she doesn't get along with the maid, Ellen. Like the rest of the household, she appears to be much happier by the end of the film.
She seems to be an older lady. She is often seen wearing a blue striped dress, with an apron and cap.
Role in the film
Mrs. Brill is first heard arguing with Ellen so loudly that it can be heard by Bert from outside the house. Inside, it is revealed that they are in a disagreement over the impending departure of the nanny, Katie Nanna due to Jane and Michael Banks having abandoned her again. Ellen is upset since she will be responsible for them if no nanny is employed. Mrs. Brill, however, seems to dislike Katie Nanna and is happy to see her leave as she says she hates her "high and mighty" attitude and face. When Winifred returns home, she is drawn into her song, "Sister Suffragette".
After Mary Poppins is employed, a change comes over the entire household, including Mrs. Brill. Not only does she now get along with Ellen, but she is so happy that she begins singing in the kitchen as she cooks. After that, she is seen only briefly throughout the film. During the "Step in Time" sequence, she is shocked to see the numerous chimney sweeps in the house and in fact attempts to hit one with what appears to be a frying pan. At the end of the film, she is seen looking on happily as a reformed George takes his family kite flying.