Who is Mrs. Bruning from Criss Cross and what is their importance?

Mrs. Bruning is Peter's grandmother. She is a feisty, old lady, who enjoys her independence and doesn't welcome her son's advice that it just might be time to move into a nursing home. She does, however, agree to having Peter stay with her for a few weeks to make repairs around the house. Unfortunately, shortly after Peter arrives she is hospitalized die to complications from diabetes. In the end, she does go home, but only after agreeing to assistance from a home health care provider and regular deliveries from "meals on wheels".