Lock and Key, by Sarah Dessen
Ruby's mother is gone and for two months Ruby has been managing on her own trying to keep up with the bills and rent and trying to stay at the yellow house. But when she's found out -thanks to her very nosy landlord - Ruby is sent to live with her sister Cora, whom she hadn't seen in 10 years, and her husband Jamie.
Cora and Jamie try to give her everything she could possibly want or need: a room in a big, fancy house, a place at a elite private school and all type of security; but all Ruby really wants is to be left alone, thinking that Cora, whom during their shared childhood, had been her champion had just abandon her years earlier to go and make her own life.
Well, things aren't exactly as they seem.
Slowly, Ruby begins to accept the help she was sure she didn't need or want, and begins to reach out to people: to her sister and Jamie, the new friends she's making and to Nate, the popular boy next door who might be in need of some help himself.
I have read all of Ms Dessen's books and it never fails to amaze me how good they are, the writing is just plain good. She writes teens that you can believe and relate too with actual problems and no facsimiles solutions. Many cameos from previous books show up, as always just to light up the page without distracting from the actual story.
A very enjoyable read, with lovable characters, a good plot and nicely executed.