Remedial Magic by Melissa Marr

The Magicians meets One Last Stop in this brand-new fantasy romance Remedial Magic, about an unassuming librarian who 1) has fallen in love with a powerful witch; 2) has discovered that she is a witch; and 3) must attend magical community college to learn how to save her new world from complete destruction by New York Times bestselling author Melissa Marr!

Ellie loves working in her local library in the small town of Ligonier. She loves baking scones and investigating the mysterious and captivating in her spare time. And there is nothing more mysterious and captivating than the intriguingly beautiful, too properly dressed woman sipping tea in her library who has appeared as if out of nowhere. The pull between them is undeniable, and Ellie is not sure that she wants to resist.
Prospero, a powerful witch from the magical land of Crenshaw, is often accused of being… ruthless in her goals and ambitions. But she is driven to save her dying homeland, and a prophecy tells her that Ellie is the key. Unbeknownst to Ellie, her powers have not yet awakened. But all of that is about to change.