Help with MIL

My MIL had to move in with us from another country because my FIL was cheating and he would be gone for days at a time. Prior to this she lived with us during COVID because she couldn’t go back due to the travel restrictions in her home country. I thought we had a decent relationship. However, she exploded in front of my SO and told me she wasn’t happy with me being there. My SO kicked her out because she disrespected me. I was pregnant before she went back home and she never said a word.

Well now that she “had” to move back in with us she is starting to over step her boundaries with our daughter as if she were hers.

My MIL has only been back for 2 months and because I never forgave her and she showed her true colors how she feels about me I can’t stand being around her.

I fear my SO will always side with his mom

I don’t know if I can take it.

It makes me upset that she might be the breaking point