RE:Eclipse volume 1

Sara was 15 when Gray Aliens attacked Earth. She became their test subject. She had 3 children. The first one died, the second one was not normal, as was the third. The Greys kidnapped the youngest child. Sara is trying to get it back. During her journey she meets Rahj, a hybrid of human and alien (Udhetar). He tells her that he is the biological father of her children. They both set off on a long journey through the galaxy to find their youngest children.