How to Train Your Demon by Julie Kenner

If you want something done, ask a busy person. Kate Conner could kill whoever first said that.
As if the full-time mom, part-time demon hunter didn’t have enough to do, she’s now been given a third job—as headmistress at a special academy for up-and-coming slayers.
Kate’s first charge? Her own teenage daughter Allie, who thanks to her unique heritage, has more power than either she or Kate understands. And definitely more than either knows how to use.
But they’ll have to figure it out fast when dark forces descend on the school, and … Seriously, can Kate just catch a break already?!