I actually quite disliked this one. I had two main reasons.
Firstly, Cassie was incredibly shallow. I found nothing to like. I cannot imagine what I was supposed to like. She was a terrible combination of selfish, arrogant, and stupid. While her declaration of "I love her!" at the end was probably intended to reflect a transformation and deepening of her character, the "tell don't show" nature of her romance with mystery chick made it feel like just another explosion of shallow BS from an overwhelmingly shallow and meaningless person.
That came out rather more vehement than I'd intended... I'm sorry, I just really didn't like Cassie at all.
Let me be a little more clear; in order to like a story I need to find the protagonist either likeable - so that I am involved in the story via sympathy - or interesting - so I am involved via fascination - or both. Cassie was a bad combination of unlikeable and boring. She was a whiny, horny, arrogant, ungrateful teenage runaway with no depth but a past of indifferent suffering lacking the wit to even contemplate her own hardships. The protagonist of The Olverung, for example, turned out to be an enormous jerk, but he was an interesting jerk. Cassie was a boring jerk, and for me, that's a recipe for story failure.
Secondly, what's up with the man-hate? As a person who was a man-child I am a little bothered by a future of hope and happiness being symbolized purely by the birth of twin girls. It's a happy future, and the sun is brighter, and they'll be a happy lesbian family forever, and all because there are no baby boys here. What the hell is up with that? I'm not accusing the story of being sexist - that's not for me to say - I'm accusing it of being thematically lazy.
All that said, I'm almost always amused by modern mythic urban fantasy, which this was, for all that it was set in a rural environment. The premise is fascinating, even if the characters and the conclusion left bad tastes in my mouth.