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

Louise is "the fat girl," the title character of this story. As the title implies, she struggles with her weight throughout her adolescence and early adulthood, finding that people value her mostly for her thinness. The only person who really seems to appreciate her for who she is is her father, who does not care what she weighs. She is loving and kind, though very possessive of those around her.