Sweet Black Waves by Kristina Perez From Goodreads: Not you without me, not me without you. Two proud kingdoms stand on opposite shores, with only a bloody history between them.  As best friend and lady-in-waiting to the princess, Branwen is guided by two principles: devotion to her homeland and hatred for the raiders who killed her parents. When she unknowingly saves the life of her enemy, he awakens her ancient healing magic and opens her heart. Branwen begins to dream of peace, but the princess she serves is not so easily convinced. Fighting for what’s right, even as her powers grow beyond her control, will set Branwen against both her best friend…