Keeper of the Lost Cities (1) by Shannon Messenger

Keeper of the Lost Cities by Shannon Messenger is the first book in a fantasy series that follows Sophie Foster, a 12-year-old girl with extraordinary abilities. Sophie discovers that she is not entirely human but belongs to a hidden world of elves. As she learns about her unique powers and her place in this magical world, she uncovers secrets that threaten both her new home and the human world she left behind.