The Wondrous World of Violet Barnaby

Eighteen months after a girl's mother died of cancer, her dad quickly marries the meanest teacher in school, and Violet acquires two step-siblings. She finds a hidden letter from her mom, with a list of things to do to celebrate Christmas. Good look at family, and how to deal with emotions and hurt feelings and pain and forgiveness. The climax is one of the most moving things I've read in quite a while. Really, really enjoyed it. Set in a warmer climate, where snow for Christmas is probably not going to happen.