Hi Kartusch,
I so empathize with you about what you are going through right now.
I would really like to encourage you to get some in-person support durinf this challenging time. I highly recommend that you check out some Al-Anon meetings in your area as these can serve as a sort of instant surrogate family, if you will, and you might find it comforting to be in the company of people dealing with very similar issues.
Making the decision to go no contact is something that you can take your time on, and it isn’t a decision that needs to be permanent. Has your sister ever done something like this before? If not, and because your daughter is older, it may not be necessary to go NC and perhaps you could find other ways of ensuring your daughter’s emotional safety during family visits. Maybe you could make a plan with your daughter in advance on how you will handle things should tempers start flaring, for example, taking a timeout by going outside for a walk to give everyone a chance to calm down. You could also make sure that your daughter is not left alone around problematic family members, and you could plan on only spending a limited amount of time, by arriving just before dinner, and leaving as soon as the presents have been opened. Or perhaps you could keep it really short, and visit just for dessert and presents, while you and your daughter go out to a nice restaurant for Christmas dinner. Yet another radical option that could be worth a shot is to host a Christmas meal yourself, on either Christmas Eve/Day, that you would invite just your brother and parents to — although they may not be willing to exclude your sister. Those are just a few ideas that may or may not work for you.
I came across an interesting website that has several books for children of parents with personality disorders, so perhaps these might be helpful for your D:
www.pdan.org/shop/books/