Please help/ give me some advice

I need some advice/rant. My mom is my best friend truly the biggest blessing of my life. She’s been in a horrible relationship for 2 years now he abuses her, brakes her phone at least once maybe twice a month, she’s not allowed to be with us (her kids for a long period of time), she isn’t allowed to go anywhere he isn’t and he talks to her horribly and be littles her. He doesn’t like any of us because we tell her how she needs to get away from him etc. recently they got into a big fight hr hit her in the face split her chin open and threw her phone down a gutter. She called us crying and asked for us to help her. She filled out a police report for him even sent him to jail for a week till he paid off her phone. Without him she came to visit us all the time, called us 24/7, wanted to do stuff with us etc then all of a sudden she goes ghost tells us she’s out of town so we weren’t allowed to call her or see her. My sister went by her ex’s house and load and behold her car in front of his house. I text her this and she answered my question so therefore I am done talking to her I no longer want her in my life until she gets hers together. She called me today yelling and cussing because all my other siblings found out and now they’re not talking to her and she felt I had something to do with it. Which I didn’t. I texted her this today after our call. My question is, is it wrong for me to no want my son to be around someone who’s okay with being abused? I’m pregnant with my first and her first grandchild (due in March) I really wanted her to be apart I even decided to spend a year in Ohio without my S.O so she could be apart of his life. But she only comes around when they’re broken up. Am I wrong? Am I taking this too far? My feelings are beyond hurt they really are.j