Cleaning Up, by Leanne Lieberman

Jess has plans.  She wants to finish high school, go to college, and start a landscaping business.  To do those things, she's going to have to save a lot of money.  She cleans houses and tries to keep her alcoholic and drug-addicted Dad from spending everything.  While there is a teacher at school who helps her (and turns a blind eye to the neglect she is undergoing), for the most part she is on her own.

While cleaning a new house during the summer, she discovers a diary that belongs to a girl who disappeared.  While she knows it is wrong to pry, she starts reading it and finds herself imagining a life with this mystery girl.  But the more she learns about the girl, the more she starts to lose her own sense of self.  Jess's success has always depended upon being disciplined and driven.  Now she risks losing that focus.

A nice character study of a troubled young woman who works hard against the odds.  There are definitely things about her I did not like.  I found her self-centered and stubborn, unwilling to accept help and dishonest (and never mind the whole invasion of privacy thing!).  But at the same time, she deals with great challenges, works very hard, and is surprisingly resourceful.  Lieberman writes in a sort of dumbed-down way that suggests that she's intentionally trying to pick up reluctant readers and I think that's an ideal target for this story of a girl coming from a lot of disadvantages but learning to navigate her way to success.