Broken Fate: Threads of the Moirae (Unabridged‪)‬

Zeus gave her one simple job: Kill every human. Atropos, daughter of Zeus and the third goddess of Fate from Greek mythology, spends her eternal life snipping human lifelines when their mortal lives are over. As if being a killer doesn't make life miserable enough, she and her Fate-wielding sisters must live amongst the humans on Earth thanks to a long-running feud between their mother and Zeus. Living on Earth means they must mingle with the mortals, attend the local high school, and attempt to fit in, or at least not stand out too much.

Killing and mingling don't mix, which is why Atropos' number-one rule is to avoid all relationships with the humans. Caring for the people she has to kill is a fast track to insanity. However, when Alex Morgan walks into her first-period English class, she knows she's in for trouble. He's the worst kind of human for her to like, one with a rapidly approaching expiration date. And he makes Atropos want to break all the rules.