Not invited to my fiance's daughter's wedding

So my fiance's daughter has uninvited me to her wedding coming up in a few weeks. My fiance and his daughter's bond is strained as it is. I met his daughter on multiple occasions and I try my best to interact with her but don't receive anything in return. She is always upset wreturn FH and she's not very close to me by her choice, not by mine. I guess I'm hurt because this is the first major event that I won't be able to attend with my own fiance. I know that his daughter is still hurting from the past and her real mother died so I understand. But it hurts me because it doesn't even seem like FH is convincing his daughter to let me go because he says she is stubborn and bitter. I'm thinking maybe it's best that I don't go anyway but I literally was looking forward to this event. My fiance and I have got our own wedding to plan and I will be the bigger person and still invite her even though that angry part of me doesn't want anything to do with her because she is a mean person. She became upset when we got engaged rather than happy. She is very immature so it's expected. Most of his relatives did not care that we got engaged. Most of his relatives are not invited to our wedding but his daughter will be an exception if she wants to go. I have a young child I will spend the day doing something fun rather than thinking about the wedding and trying not to drink my stresses away that day. Can anyone relate? Any advice on how to keep myself sane through this process? I do understand that that is his daughter and he has to attend her wedding. I want him to have a good time and enjoy his family but I also know that weddings are a romantic event and I dont want to miss out but I'm going to have to because she has completely made up her mind.