Star Steel - M N Jolley - Bog

Maggie Cartwright never expected to find herself as a mercenary, never mind one facing an apocalyptic threat the world hasn't seen in living memory. A solitary auto mechanic and a smith by trade, she's more comfortable making blades than using them. Slaying monsters professionally is a difficult, hazardous job that's as likely to end with fangs in your throat as a solid paycheck, even for professionals working in a team.
But in the land of the fae, fate doesn't care what she's comfortable with, and for Maggie, the danger of razor claws and ancient magic pales next to the danger posed by her own people's politics. Monsters can kill. Manipulation by the fae can do far more damage.
Maggie's talents as a master smith make her valuable, and her former mentor's legacy makes her a target. With a city on the line and hellish monstrosities digging their way up from the deep, Maggie can't refuse the call to fight, and the battle cannot be won without allies. With the right friends, she could save hundreds of thousands of lives and get paid doing it. But if she can't learn who to trust, she won't be the only one who ends up dead. ... The following work contains depictions of verbal abuse, violence and mortal peril, death, mild gore, and peril to teenagers in a school setting. Reader discretion is advised.