I've NC for this...
My DF is in his 80's and we (all siblings plus DH's, children around 20 in total) have taken him our for a meal. I've only been going for around 5 years as previously we lived around 150 miles south.
My DB (who also never attends due to living at the other end of the country) recently found out her had a daughter from a one night stand when he was 20, she also lives locally. Once over the shock, we welcomed her into the family.
She is not a very nice person, very loud and obnoxious and it would take me too long to tell you about what she has done in the last 14 months since we have known her, but we have persevered with accepting her as family. The last straw for me was at the family Christmas meal out where she actually started fighting with some other people in the restaurant. It was truly horrible, we are a quiet family and we were all mortified. The fight resulted in us being asked to leave! Afterwards I had a quite word with her explaining that she would not be welcome to any further meals if she couldn't respect the rest of the family. She didn't take too kindly to this and told me to "fuck off and to take my black bastard's with me"! (My DH is black and I'm white so our dc are mixed race). She was drunk (again) though to me that's no excuse whatsoever.
I've not spoken to her since and whilst some of my siblings speak with her I don't really care if I never see her again. Two of my siblings have encouraged me to let it go... but I can't.
Anyway it's DF birthday meal and she has been invited... I know I should just go and grin and bear it for DF but frankly I don't want my DH or dc anywhere near her.
AIBU to not go...