How does Stephanie change over the course of the novel, Those Summer Girls I Never Met?

Initially, Stephanie is described as a creature formed by MTV, Cyndi Lauper, the phone, and the mall and is aware only of her own desires. She needs the awareness of another person's will, a wall to butt against. Over the course of the novel, however, Stephanie learns of her grandmother's cancer, which is like the discovery of a new world. She learns to respond to the needs of others and is no longer driven by her own imperious will.