Iron Champion. Legend of the Iron Flower, #5

Action-packed fantasy adventure with a powerhouse female epic warrior in the spirit of Achilles or Beowulf. The continuing saga of a warrior whose army-slaying sword belies her kind heart. Nearly indestructible heroine Rose gets a letter from a foreign king inviting her to discuss opening a new branch of the center for magical study she helps run. Upon arriving in his kingdom of Terlon, she learns that his true motive is to request her aid against invaders from a larger country.
Though annoyed by his deception, her compassion does not allow her to turn a blind eye to the suffering of his people and she agrees to help. Following unfavorable developments in the war, Rose finds more and more responsibilities being heaped upon her shoulders. A bitter dispute breaks out over the leadership of Terlon with her caught in the middle, and a battle with the enemy nation's war god looms near.
But even that might not be the most daunting trouble fate has planned for her. A full length novel. Fifth in the Iron Flower series.