What a tough spot. I'm so sorry that your daughter, and you, and going through this.
One thing that stuck out for me, though is: you said that her boyfriends' parents don't like her. Should she terminate her pregnancy, or give the baby up for adoption, and she marries this guy ~ what will the family dynamics look like in a few years?
Personally, I think he is incredibly selfish to even suggest such an ultimatum.
Prayers for all of you.