More mother in law issues.

Okay so I’m posting this anonymously because last time I posted something about her she found it and bashed me for speaking about her on here. I’m really just at a loss of what to do. We recently moved into my moms house to help us with taking care of my two kids while my fiancé goes to school and works. We went to visit my fiancé’s Parents’s for almost a week before we left to go live in another state. During that week things where fine everyone was getting along but then the very last day I was sitting on the couch with my daughter and she was outside with my fiancé, his two brothers, and his step dad. I soon hear her start talking badly about me. After listening for alittle bit I had enough and I walked outside. Everyone went silent and I said “please continue your conversation since it was about me” his step dad then goes on to say “I told you, you need to stop talking about her behind her back” let’s say it lead to a pretty heated argument but I was really tired of being talked down on since this has been going on for years. After the argument she apologized and again I thought things where fine. Then today she is on FaceTime with my fiancé and she starts talking badly about us and me again. I step into the conversation ready to stand up for myself again and she says I’m not fucking talking to you this is a conversation between me and my son! Blah blah blah and hangs up. I message her this.

In the text after to my fiancé she accused me of getting tattooed while pregnant which I would never do and have not done. (I’m 33 weeks pregnant) She also called me a piece of trash in her text messages to my fiancé. I really just don’t know what to do.