Once she has the abortion, they will ship the boy off to boarding school somewhere or otherwise break up the relationship. She is now a constant reminder of their precious son's "indiscretion" and they will get rid of her whatever it takes.
And, anyway, how does she think their relationship is going to continue with the shadow of a baby, murdered for his parents' convenience, between them?
She CANNOT keep his parents happy. Except by disappearing from their lives. If they are willing to make their own grandchild "disappear" they will be only too willing to make HER "disappear."
She needs to realize this because she is setting herself up for an even greater tragedy. She will still have killed her baby, and she will not have her boy that she supposedly killed the child for. And then she won't have to "imagine" life without him.
When I got married some years ago, my husband's son was paying child support for a child he had help conceive at 16. His mother wanted her son's girlfriend to have an abortion, but changed her mind after she held him after he was born (she died soon after and was glad to have had the opportunity to hold her only grandchild). My step-son was able to support the child and go to college because the entire family supported him--both emotionally and financially. This family could too. Now the young man is 27 and as it turns out, it's really the only responsibility he's ever had in his life. I shudder to think what he'd be like if he at least hadn't been forced to do that!