When Tish's Englishteacher, Mrs. Dunphrey assigns a journel, Tish knows it is a bogus assignment, especially since the teacher has said that they can write whatever they want and put "Don't Read This" on the entry and she'll respect their privacy. But when Tish starts to test that promise by writing about what is really going on at home, she acquires a mirror that shows her just how much her life is falling apart.
This is another of those stories about a teen trying to survive with disfunctional parents (See Room on Lorelei Street for example). They are harrowing stories of neglect and abuse and make for good melodrama, but I'm not sure what purpose they serve otherwise. The plot certainly sucks you in and the conclusion is a tear jerker, but in the end, what have we learned?