Iron Flower — Billy Wong

One of the greatest fighters in the world, nearly indestructible Rose lets few things strike fear into her--but magic is one of them. Nonetheless, she seeks out the magical dangers left by the ancients alongside warrior partner Finn and curious scholar Derrick in order to protect others from them. Their mission is complicated by Rose and Finn's budding romance, as her choice of lifestyle conflicts with his expectations for the woman he loves. But after their quest pits against such titanic foes as a prince able to slay a thousand men in a day and a draconic archmage, will Rose be forced to embrace the very magic she fears?

A full length novel. Second in the Iron Flower series, but you do not need to have read the first to enjoy this one - either is a great starting point to the adventures of Rose.