MIL and baby’s sex

Okay so my mother in law and I have an odd relationship. She is a nice woman, don’t get me wrong. But she is also emotionally unstable, has a problem with substance abuse, is overbearing and completely lacks any boundaries. During my first pregnancy I felt like her incubator rather than a human, and she’s already doing it again this second time around. Now, she is obsessed with having a grandson. She was obsessed with the baby being a boy when I was pregnant the first time to a point where it was really crazy and obnoxious. When we found out we were having a girl I was thrilled - one, because I was really excited it was a girl and two, because I didn’t have to deal with her going completely bananas over the golden child boy. We just found out baby 2 is a boy 💙 personally, I am super excited. What I’m not excited about is telling her bc I know she’s just going to drive me crazy. Not only will she be obnoxious but I have this feeling that she is going to be extra no-boundaries with me knowing this one is “her boy.” She already kisses my (non-existent) belly and generally acts like she owns me. I’m petrified she is going to get even worse. Does anyone have any advice for getting her to back off of me? This is giving me stress!