Who is Jane from Wasted: A Memoir of Anorexia and Bulimia and what is their importance?

Jane is the recovering anorexic about whom Marya writes in the introduction to her story. Jane is rushed to the emergency room by Marya when Jane complains that she is having heart palpitations. Later in the book, Marya mentions the first time she meets Jane. Jane is eating an apple in what Marya describes as an erotic fashion. Even Jane tells Marya that she is "making love" to the apple.