Scylla: Immortal War Series Book 4

Scylla thought she was normal, with a normal home life, and only the normal oddities of being a teenager to cause her angst. Everything changes during her senior year in high school when she discovers that not everyone lives with demons, gargoyles, angels and vampires, and not everyone has a crazy group of people who are actively hunting them down and trying to kill them.
When you're the granddaughter of some big-name gods and the daughter of a well-known, mass-murdering demigod, life can be really weird.