Should I even tell my MIL? 🙄 PLEASE GIVE ME ADVICE!!!

I got pregnant at 15 back in 2015. You women might say I was too young but I was capable of taking care of my child. I was getting money, the clothes and necessities, EVERYTHING. Meanwhile, my SOs parents had put him on probation from talking to me and said my baby was not his because I was a “whore” (they didn’t even know me and was supposedly “Christian” )

My now MIL decided to tell me that she was not going to claim the child and she was not letting my SO claim the child until she knows it was his. She went and bought a DNA. And before i proved her wrong I told her and my SO “you can take the dna, but when you do and it turns out that you’re the father, SHE WILL NOT EVER COME AROUND MY CHILD.” He agreed and understood.

Fast forward to a year or so, they got the DNA back and sure enough he’s 99.9% the father, my son is born and he’s 3 months old. I brought my son to see his FATHER. When I get here, my MIL was sitting in the house waiting on him. I take him in to see his father and she snatches him. Starts taking pictures with him and posting them on social media saying “love my grand baby”

I moved in with him and his parents when I was 16. (Worst mistake of my life but had to get away from my drug addicted mother.) and my SO signed his rights over to his parents and admitted he was not mature enough for a child to be in his custody. (Our son was around 1 now) I still had part of my custody which my MIL did not like. Throughout my sons life, everything I done was wrong. She even got to the point of her saying “I FEED HIM WRONG!”. She always tried being the mother figure to my son when Im a great mother to him and no one could take my place. Since then mine and my SOs relationship had fell down hill and my MIL disliked me even more. She was constantly snatching my son and taking him out of the room with her. This woman was just saying I was a whore and that the child was nothing to her.

I now live with my SO now. We have a house of our own. So rewind about a year ago, some issues went on and they basically forced him to kick me out. They kept on and on until he decided to call the cops on me. (Not sure why they even had to get the cops involved). Before I left, the cops said I could not take my son (I still had my part of custody) and that if I tried I could go to jail for “disturbing the peace”. I left without my son and that was the worst moment of my life. So I started living with my sister. I literally lived with my sister for around a week until my SO told me I could come back whenever I wanted. Next thing you know, I get a message from his mom saying I had to sign my rights over to her or else I couldn’t move back in with my SO and I couldn’t see my son at all. So of course I signed them over just to be able to see my son for what I thought was for a year. Turns out, she put on the papers that I was signing my rights over completely for ever. I asked her about it and she said she would get it fixed, she never did and still hasnt.

I now have my son 90% of the time and the only time our son is up at her house is to go to bed (because we are redoing his bed room here and making it bigger). She has now called herself his “momma” and when I correct her and him both, she says “he doesn’t understand. I’ll tell him later on “ and has also got our son calling my FIL “daddy”. My SO and I are extremely pissed and have been trying to talk to her about correcting him and herself. But she will not.

We just found out we are expecting baby #2 and we planned to keep it as a secret until we know the baby is healthy and perfect.

At this point, I REALLY don’t want my MIL or FIL to know anything about us expecting.

Should I tell her?