Am i wrong/overreacting?

So my husband and i moved in with my mom and step-dad to save up some money to buy a house. We had talked about them not budding in on our parenting but they do it anyways. My mom is attached to my 6 year old son but not my 3 year old daughter. He’s the one that always gets to go places with her. I’ve never been super close with her due to the fact that she gives me anxiety. But recently she’s been threatening to call cps on me. She states that we abuse our son and says she plans on showing them videos of me drunk. The only times she has on video drunk is when there’s a party where everyone including her is drunk. That couldn’t be father from the truth. On top of that she belittles me and tells everyone that i don’t do anything. I’m a stay at home mom but have been looking for work recently since both kids will be in school the coming year. I’m just so tired to the point where i want to move away and cut her out of my life.