Who is Peggy from Up in the Old Hotel and Other Stories and what is their importance?

Peggy is a regular at Madame Visaggi's spaghetti house, Peggy was very self-conscious about a birthmark on her face. She sought acceptance but seemed to worry a great deal about the birthmark and what people thought of it. When a little girl made note of the mark, Peggy frightened her so that the child became almost hysterical.