Another child of the eldest gods

This is Alexandra 's first year at her new school John Addams secondary school . she has just moved from L.A to New York. soon she finds out that she is a half-blood. Now her protector gale must get her to camp half-blood. When she gets there strange things start happening and she discovers she is the sister of a very famous demigod. She and some other demigods friends must go on a quest to save the world .