Poppy Pym and the Pharaoh's Curse by Laura Wood
Winner of the Scholastic Montegrappa Prize for New Children's Writing = Poppy Pym has grown up in the circus, taming lions before lunch and learning acrobatics in the afternoon. But when she turns eleven, her circus family decides she needs a more traditional education, and she is sent to boarding school. At first Poppy doesn't fit in at St Smithen's, a school that is very different from the circus. Then, an ancient Egyptian ruby arrives at school and dangerous accidents start occurring. Suddenly it's up to Poppy to save her new school and solve the mystery of the Pharaoh's curse!