Tina,
You’re in a tough situation! I’m glad your son wants to accept responsibility and you are both pulling for the baby. How does your son’s girlfriend feel about the pregnancy? Had she expressed her feelings about it and what she wanted to do to your son before her mom prevented her from seeing your son?
I’m guessing her mom was pretty much in shock over the pregnancy at a young age especially if she was not aware that they were sexually active. Perhaps keeping her daughter from contacting your son is her form of punishment to her daughter for what she views as misbehavior or to keep her daughter from continuing to have sex. Were you aware that they were having sex? If so she might also be upset with you.
Have you tried talking to her mother? Perhaps if you approach her mom and say that: no the two probably shouldn’t have been having sex, and the pregnancy is not an ideal situation, but that you care about your son, his girlfriend and your future grandchild and want to make the situation right. Is your son willing to stop the sexual aspect of the relationship? Perhaps if they agree and stick to the pledge to refrain from sex together she would be more willing to let her daughter see your son. Maybe it won’t work but it could be worth a try. Perhaps adoption could be an option also.
Sadly teen fathers have little legal say to prevent their children from abortion. I don’t think her mom could physically force her to have an abortion but under extreme pressure many girls have sadly been practically forced into abortion by their parents. Best Wishes and good luck!
Kate