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

Evie's mother, Mrs. Kimball, is a trained practical nurse. She cares for Martha Wallis after Mrs. Scallop leaves to take a job at the nursing home in Waterville. Mrs. Kimball is described as a kind and patient woman, who isn't a very good cook. Ned's family prefers Mrs. Kimball to Mrs. Scallop.