What should I do?

So my mom has a dinner party (we always go to a restaurant) every year on Christmas day.

Now this summer I was visiting her and I told her about problems in my marriage.

Now.. my mom and I never really had a great relationship, she always made me feel like I was crazy, completely out of my mind bonkers. She would tell me this also. And she would tell me that I'm victimizing myself when I told her I wanted her to act on the fact that my brother was beating me up frequently. - she never did - I always tried to move past. We went to therapy and the therapist told me that while my brother admitted to beating me up but was not feeling any remorse, regardless of not having a good reason to beat me. My mom GENUINELY felt like it never happened. So I think I kind of moved past because she believed nothing was wrong so why act on it. Like if I believe blue is blue and has always been blue, you're not going to convince me it's pink, is what I have always compared it with.

Anyways so my mom never had much interest in me after I moved out. She had some flare-ups when I had just got a dog and then she'd come visit with stuff for our dog.. and then when we had our son, she'd come in for my son. Which seems to amplify the idea that she's never here for me, but always for my entourage. My partner knows what went on in my family and why I moved out at 17. He has shut down contact with my mom pretty early on. So when she's visiting he's often not home.

Well. This summer when I went over (there was a historical evening event in my home town and since my brother moved out, we could sleep in her house. it was just me and my son) So to get to the point of my story (not quite but hang in there, sorry!) When I told her about my marital problems, she told me that is exactly why she and my brother never liked my husband, while she did actually like him and he was avoiding contact with her (I don't have contact with my brother anyways) but she also told me details about my father allegedly abusing her during their marriage. And I'm not sure if I should believe her. Because they were very "classic" with the general idea of abuse and watered on with what I had told her but "one up", Because of the look and her body position she shared. It made me feel very uncomfortable, asif I was having a chat with a cheata ready to devour me, it felt absolutely ingenuine. Because I don't want to see my dad as an abuser because he's the only one in my life who has actually been good to me. Because there were inconsistencies in her story. Because I am aware that she lies as she had made us lie in the past and she has lied before about my father being abusive but at that point she was claiming the abuse was towards us and my memories were very different than what my mom told us.

Anyways so I decided to no longer push to having a relationship with her after that incident this summer. So now December has started and she hasn't communicated plans for the 25th. and I don't want to ask her for the plans. but I also don't want to be rushed last moment because "you know I always do a thing on Christmas day". Also with my brother moving abroad, I don't know if she wants to do it. I don't know if he'll be back for the holidays.