You should read The Fallen Kingdom by Elizabeth May (summary for book one of the trilogy is below, because avoiding spoilers)
She’s a stunner.
Edinburgh, 1844. Eighteen-year-old Lady Aileana Kameron, the only daughter of the Marquess of Douglas, has everything a girl could dream of: brains, charm, wealth, a title—and drop-dead beauty.
She’s a liar.
But Aileana only looks the part of an aristocratic young lady. she’s leading a double life: She has a rare ability to sense the sìthíchean—the faery race obsessed with slaughtering humans—and, with the aid of a mysterious mentor, has spent the year since her mother died learning how to kill them.
She’s a murderer.
Now Aileana is dedicated to slaying the fae before they take innocent lives. With her knack for inventing ingenious tools and weapons—from flying machines to detonators to lightning pistols—ruthless Aileana has one goal: Destroy the faery who destroyed her mother.
She’s a Falconer.
The last in a line of female warriors born with a gift for hunting and killing the fae, Aileana is the sole hope of preventing a powerful faery population from massacring all of humanity. Suddenly, her quest is a lot more complicated. She still longs to avenge her mother’s murder—but she’ll have to save the world first.
The first volume of a trilogy from an exciting new voice in young adult fantasy, this electrifying thriller combines romance and action, steampunk technology and Scottish lore in a deliciously addictive read.