I had a daughter similar to yours, I ate a lot of crap to see oldest Granddaughter, when she turned 18, she moved in with us, 5 yr.s now. She doesn't want to ever see her Mom again. She went through much mistreatment from Mom & Step-Dad, he made good money, didn't want to waste any on DGD, Mom the same way, DGD had to do most of what Mom should have done around the house, Mom did anything but housework. Mom decided to get on illegal drugs, other 2 kids belong to Step-Dad, he has custody, we now have a good relationship but, I don't forget, DGD doesn't either.
Good luck, no Grandparent rights here either. Lots of kids end up like this, you were a glorified babysitter and provided her with a home to live in. When a loser came by she ditched you and oldest Son for him. Not much of a Mother in my humble opinion.