The Dear One by Jacqueline Woodson

Feni has had her mother to herself for a long time. So when her mother takes in Rebecca, the pregnant fifteen-year-old daughter of an old friend, Feni is furious. Rebecca’s just as unhappy; she feels like a charity case. But as much as they resist it, Feni and Rebecca might just become friends. After all, Rebecca needs someone to confide in, and Feni might discover she has room in her life for one more person—or even two. This is a touching story about families of all sorts, even the unrelated kinds, and the love that holds them together.