Hi Pericat
Just read this what a shock for you all, but at least your son has felt he can talk to you. I expect there are alot of lads given his position would have kept quiet.
I'd like to say although I don't want to worry you but if the father of the other 2 children is in prison, is this girl thinking of resuming her realtionship with him when he is released? What will he think towards your son? Could this be the reason she wants the child adopted?
My sister gave a child up for adoption - when she was quite young and at a confused time in her life and to be honest I think it was the best thing she could have done. She had no means of supporting herself. We didn't find out about it until she had put the adoption process into place, although I couldn't have done anything about it as I was fairly young and struggling myself.
I think about the little girl often but am comforted by the fact that she ahs made the life of a coupleso very happy and complete.
It's a hard decision all round. Hope all will be ok.