Inviting Horror

Hi All New to this so please bare with! For reasons I don’t really want to get into, my fiancée, his brother and his brothers girlfriend - none of us speak. She caused a big drama about 2 years ago to which my fiancée wasn’t very happy with his brother for not taking any kind of responsibility for her actions - huge issues for a while. We have tried to offer the olive branch at least 3 times but she wasn’t interested (despite her being in the wrong) and we haven’t spoken since. It was uncomfortable at family meals etc so my partner decided he didn’t want to attend anymore which was sad because we miss out sometimes. Still have a great relationship with FMIL/FFIL but this has caused massive strain on the relationship between 2 brothers which obviously is heartbreaking. So we got engaged at the start of the year and the difficult conversation has come round of invites. Fiancée and his brother hardly talk anymore because of it all but I just don’t feel comfortable inviting her and fiancée agrees. The turmoil she’s caused within the family is just too much and a really selfish part of me just wants it to be about the 2 of us - without us being uncomfortable on our day. I know some people will argue that this might cause more problems between brothers but it can’t really get any worse. I think I may think differently if my fiancée wanted her there but he doesn’t. I’m genuinely a pretty placid person but this is just something i don’t want to move on. Any advice or anyone that’s been through something similar I’d be grateful. Thanks.