<human>: So, I dated my ex for about a year and a half. Throughout all of that she was manipulative and verbally abusive. She would also slap me on the chest/back/arms whenever she got "surprised" or happy about something. I asked her repeatedly for the entirety of the relationship to not do that and she refused to stop. She also has on several occasions threatened to punch me in the face during arguments and has said "What are you a pussy who is afraid to get hit by a girl?"

During the year and a half, she developed a close relationship with my mother. When I broke up with her, my mom was upset with me. 

So now, my mom is still messaging her on Facebook and she liked a post by my ex that said something about her "deserving love". I have asked my mom repeatedly for the past couple of days since we broke up. She refuses to stop talking to her and supporting her. She refuses to acknowledge that my ex-girlfriend was abusive and tells me I made a mistake by ending the relationship. 

I cannot move on from this if my mom is still talking to and supporting my abuse ex-girlfriend. How do I get her to stop?

Sorry for any formatting errors, I'm on mobile.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: broke up with abusive ex-girlfriend. My mom still talks to, and supports, her. How do I get her to stop?