Who is Mrs. Scallop from One-Eyed Cat and what is their importance?

Mrs. Scallop is the Wallis' housekeeper. She is described as a stout, short woman, who is given to silent rages and superstition, and who often refers to herself in the third person. Mrs. Scallop later takes a job at the Waterville Nursing Home and leaves the Wallis' employ.