We think we found her... help?

There was no contact info on either of the listings, I found her FB through chance and the fact that she (and we) all still live in the same town. There was an attorney listed, but no adoption agency, I do not have all of the facts but I'm pretty sure the adoption happened about 3 days after he was born. The story I have is that he was left at the hospital so I'm not sure how exactly it will all work. Since finding this information he hasn't made any effort to talk to his a.mom even though she said she'd help us. I think he may be having second thoughts or it really just isn't a priority to him. I'm not even sure if I should bring it up to him or just let him set it aside. He is the type of guy who if I don't remind him of things he forgets to do them. Not that he doesn't want to do them, he just forgets because he has so many other things going on. I just don't understand how something this big would fit into the category of things that get forgotten unless he doesn't want to move forward. I just don't know what to do. I don't want to push him because it is his decision, but I don't want him to forget about it either. Any advice on the step BEFORE writing a letter?