Demon Lord's Favorite Vessel

She butchers pigs for a living and she is married to the lord of the demon realm, who has been gentle with her since the day she came to him. She is carrying his child. Close to the birth she finds out what the marriage was for. Her body was chosen to bring the child to term, and the child is meant to bring back the spirit he has never let go of. The woman who raised her for twenty years, the one she calls mother, was put in place by him to watch her and to feed her poison a little at a time. She is poisoned and in labor and near the end of it when something in her blood comes loose. Ten thousand years ago the daughter of the Heavenly Emperor was lost into the human world, and that is who she is. Her father comes down for her and exposes the spirit's lie. The twins she is carrying take on the divine side and the demon side both.