Annabel is spending Christmas Break in Australia with her father and his new family. At first she doesn't like them, and only wants to spend time with her father. As the story unfolds Lucy and Annabel become more like sisters than they ever thought. Annabel realizes how much her step family cares for her when she and Lucy run away to see Lucy's grandmother. With plans of her mother getting married and having a child Annabel realizes that both her parents love her even though they are separated. A nice read about the craziness of having step siblings in another country and also here in the United States.
Also recommended Gingerbread by Rachel Cohn.