Rosefire by Carolyn Clare Givens

Asael is a kingdom in crisis. Perhaps it is a coincidence that Anya arrived on Karan’s doorstep—without a past and with great skill in magic—the same night that Crown Prince Loran died, but Karan is not certain she believes in coincidence anymore. Rosefire is a story of friendship, redemption, and sacrifice. As Karan and Anya, along with Karan's brother Richard and friend Edmund, begin to seek the promised Rose of the Ancient Writings, they learn that the destinies of kingdoms are forged, not always in the heat of battle, but in the hearts and minds of their leaders.