Hi there tgrlily, I am brand new to your story but I have now read pretty much the entire saga. Want to add my voice to the long list of people here who think you are awesome beyond words for doing the right thing for your son and being an amazing mom and person through all these awful events.
And congrats on your very quickly approaching birth of your new baby!
You have so much to think about, but one thing that I didn't see addressed (maybe I missed it) - you mention a couple times that your son gave you more details of what happened with your ex a couple of times, and I saw someone ask if you gave the new details to the DA but didn't see you mention that. Does the DA and do the police now know everything that your son has said about inappropriate behavior on your ex's part?
And please know (this is to all the mamas out there) that in the awful event that you have to deal with things like this, if you ever call the District Attorney or child welfare or even your own lawyer and they make you feel like they don't want to talk to you or like you're annoying them... IT DOESN'T MATTER - say what you have to say and make sure it gets documented no matter what.
This is another level of having to trust your instincts, and if your child or anyone tells you something that feels important, even if a lawyer thinks it isn't there is no harm in making sure those details are documented. I work for a child welfare agency and unfortunately I know for a fact that even childl welfare workers sometimes are so overwhelmed, they'd rather not know info that will "make more work for them" even if it's relevant to their case. That's not the norm, but it happens.
And I just gotta say, although this almost amounts to ancient history now, when I read that your inlaws were staying with you and watching your son, my first reaction was "Oh no, they are trying to gather evidence against her!" I'm SO relieved that even though they got very frosty and made it clear they were supporting their son, I'm so glad them staying with you didn't make things even worse adn that they didn't try to talk your son out of his truthful story. I was really worried about that as I kept reading.
You are a star, you truly are, and while I know your new baby will bring all sorts of new joy but also stresses on you, I hope somewhere you get the chance to step back, look at how you have handled and are handling this situation with your son and your ex, and you can say "I f'in RULE! I am truly Wonder Woman to have done the right thing and endured all this stress!" Because that... is the truth!
Take care, wishing you and your new baby a safe healthy birth and wishing you, your son, your new baby and anyone else you become a family with in the future a long, happy, healthy, SAFE life! Wishing that to all of us on this board......