Falconer trilogy (Elizabeth May)

Edinburgh, 1844. Beautiful Aileana Kameron only looks the part of an aristocratic young lady. In fact, she's spent the year since her mother died developing her ability to sense the presence of Sithichean, a faery race bent on slaughtering humans. She has a secret mission: to destroy the faery who murdered her mother. But when she learns she's a Falconer, the last in a line of female warriors and the sole hope of preventing a powerful faery population...

Aileana Kameron, debutante and faery huntress, has been resurrected by ancient magic and given the dark powers of the Cailleach in an attempt to break the curse that pits the two factions of the Fae against each other in a war that could destroy both the Fae and the human world--but as she gathers her allies for the final battle, her new powers are slowly destroying her.