Sorry for the long story.

A little back story. Two years ago my sister(39) started a fight with my daughter(21). My sister offended her repeatedly and my daughter decided not speak to her again. My daughter is mixed race and my sister is white. My sister reportedly made some racist comments and was trying to convince my daughter they weren't. Trying to convince my daughter that not everything is about race, bla bla bla. She wasn't listening to my daughter one bit. Then my daughter had enough of it and cut her off. My daughter told me about their problem from the one and I use to ask her if she wanted me to interfere, which she clearly didn't want so I stayed out of it. I offered her many times to talk to my sister but she really didn't want that. My sister lives in a different country and is mostly communicating through messages which my daughter showed me, so I know what was said. At some point my sister even went to cry to my parents which then called my daughter. During the 2 years my sister did not call me once to let me know what was going on. This Summer she came to our country for holidays, not to see us also not the first time she came. Last time she was here she didn't even come to see me and my family, but this time she made sure to come and see us. My daughter wasn't home the day she came. When she was here she started talking about my daughter and trying to defend her own behaviour which got me so angry. My husband bless him, was trying to calm the situation. And we kind of parted amicably. There are some other shit she pulled over the years and I'm not gonna lie, at this point I don't even care anymore. I just don't feel anything when it comes to her. My husband always thinks I should make up with her because she is my only sister, but I just don't have it in me.

But now to my dilemma. We are going to visit my parents for Christmas, we stay at theirs. And I'm almost 100% sure that my sister will be there at some point. My parents are getting old and the last thing I want to do is to bring drama to their home especially on Christmas. And I also do not have the mental capacity to have an other altercation with my sister. I'm really threatening this Christmas and I'm not looking forward to it at all.