Bayou Moon (A Novel of the Edge Book 2)

Cerise Mar and her clan are cash poor but land rich, claiming a large swathe of the Mire, the Edge swamplands. When her parents vanish, her clan's long-time rivals are suspect. But all is not as it seems.
Two nations of the Weird are waging a cold war fought by feint and espionage, and their conflict is about to spill over into the Edge-and Cerise's life.