My daughter was absolutely hooked on Running Out of Time last year (and she was ten then). I can't remember the author's name, but it's historical fiction with a time traveling twist. The story is about a girl named Jessie who has lived her whole life in a frontier pioneer town. The whole town is very concerned about the typhoid (?) that's sweeping through the town; a few children have even died. Jessie's mother takes her aside and admits to her that her whole life is something of a lie: They're part of a historical exhibit, and people come to watch them every day on secret cameras. She's not over her outrage yet when her mother dresses Jessie in a pair of hidden blue jeans and sends her out of her comfortable life in search of medicine for her friends. She's never seen a car, never had a soda, and certainly never been out on her own.