Marina's Tales, book 2 : The Moon and the TideDerrolyn Anderson2011

Just when things seem to be all figured out, Marina discovers that there's a lot more going on behind the scenes than she ever imagined. When a terrible accident exposes her secret, she discovers that her whole life has been one big lie, and has to cope with more than one kind of betrayal. A dangerous enemy arrives on the scene, putting her bravery to the test and forcing her to use all of her new-found talents to protect her family. Will good win out over evil? Can love triumph over jealousy?