Close to Famous by Joan Bauer
Foster has issues out the wazoo. Her and her mom left her home in the middle of the night to escape the rampage of her mother's ex-boyfriend, an Elvis impersonator, who was getting creepier, and creepier. And she can't read. For every time she has opened a book, something shuts down, and won't let her read the simplest words. But she, and her mother, are not giving up. They find themselves in a new town, with new opportunities. And who knows? Maybe is she can do the impossible, teach a scaredy-cat aging actress to cook something as simple as a hamburger, maybe she can teach her to read. And she is going to need to read if she is going to become famous for her cooking.