I'm really sorry, Karma.
I don't have much for advice but to say I've seen this a few times with relatives.
And you sound like a very caring person-I hope that grandbaby will get to have you in his or her life.
There is one instance where a relative didn't know about her grandchild until the baby was three years old. The father claimed a ONS -very, very young, these parents-and the mother, when found, told my relative she didn't want anything to do with them. She didn't even know the paternal grandmother but the lady has no choice or part in the child's life and doesn't think she ever will.
She did insist the son have testing and all the whatnot and he would claim "the answers got lost!" several times.
So I hope that you will have an easier time than this grandma did. FFWIW, this is also in MA.
The same family has another grandchild OOW (out of wedlock) and he or she is basically being raised by the grandparents in this case. What was sad was when the court appearances began, the father was going to try not appearing. He had no idea that he may chance forfeiting the child's right to it's other relatives, like if he were to sign away his rights or pull a no show.
So no real advice, but good wishes and some examples I knew of to share. The latter example is a pretty wild little person, without many boundaries and with a bunch of ailments who goes back and forth between homes. But they are doing their best by the child and at least he or she had someone like you, Karma, to stand up for them.
Yes, going to a family lawyer is a really good idea. This has been done in both instances that I related here and sometimes, like in my own life, just being able to say "I asked a lawyer's advice", can go a long way. Maybe it's a good place to find some comfort and there are some who do free consultations, I believe?