Who is Mrs. Peavey from Tender at the Bone: Growing Up at the Table and what is their importance?

One day when Mother has a fancy dinner party, Mrs. Peavey accidentally drops the Beef Wellington on the dining room floor. She immediately tells Mother that she will go into the the kitchen and get the other one. Back in the kitchen, Mrs. Peavey uses scraps of extra dough to cover the cracks in the Beef Wellington, and proudly takes it back into the dining room. Later, Mrs. Peavey shares her three important life lessons with Ruth. First, do not let other people tell you how to live your life. Second, take care of yourself. Third, always make extra pastry for the Beef Wellington.