Wedding fall out with best friend?

This is still a sticky issue and people, unfortunately, feel passionately one way or the other about this. You love your sister and your bf. Perhaps she thought she could handle it, then found out she could not. It is obviously something that she is having great difficulty dealing/coping with. Make the first move, talk with her in private, honestly, openly as only bf's can. Tell her you miss her and want her to be a part of her big day. Tell her you respect her opinions, we each have one, but ask her if she can put hers aside as it will mean the world to you to have both your bf and sister with you on your special day. If she can't get past this issue long enough to share your big day, then it is sadly, her loss. Hard to let go, but if she can't, she can't and you have to accept that no matter how hard. Sorry, but just calling the shots as I see them. Some people just really have problems with people who in their eyes do not fit the "traditional mold". Good luck, maybe after she has time to think it over, she will come around after having some time to think this thru. Best wishes!!!!