Most important, is the girl living in the dirty trailer park with the boyfriend who has emerging anger issues? If that is the case, let her know in no uncertain terms that she and her baby are always welcome at your house if/when they need protection from him. Otherwise, tell her that you're there for her and the baby and that you will support her in whatever decision she makes about keeping it or giving it up for adoption, with work and education. But the boyfriend needs to get a job YESTERDAY!
If she keeps the baby, celebrate the new life that's coming into your family. Every baby deserves that.