Who is Valentine from The Vintage Book of Contemporary American Short Stories and what is their importance?

Valentine appears in a number of different stories in the collection. She is one of Colette's closest friends, and she is described as a kind-hearted woman, whose company Colette seems to enjoy. Valentine, however, also has a tendency to be slightly superficial and shallow..... preoccupied with fashions and other people's lives. Like many women of her time, Valentine is preoccupied with appearing young, and she is baffled when her lover breaks up with her because she is too painted and false-looking.