[Sundae]

MoreThan, I'm happy you've squared things with your sister, and despite what you think about her wedding you are rising above it to give her what she wants.
I wish like anything I had such an open and honest relationship with mine - I never told her what I felt about her husband to be, it was all unsaid and she resented me. And has ever since, really. We lost open communication around that time anyway, but I'm pretty sure she just found me intolerable after a certain age.

Of course you can dance, darling.
And if you don't know so now you have it to look forward to.
All you have to do is not to care. I hated it til I was about 23, have loved it ever since.

I'm afraid the things you've asked advice on are American traditions, so I can't help much.
One thing I found worked, and might do for your "bachelorette party" (we say hen night, but that is a very different thing!) is to go around the table or group and ask everyone to say something positive about your sister. If it's not a sit down meal, then maybe ask for slips to be filled in prior to arrival (anonymous if necessary) which will be read out at the party. It's a lovely thing for a bride to hear a stream of positive comments.

Otherwise - games, games, games. No idea what this party is s'posed to be like, but I know any group of people unknown to eachother need ice-breakers. If you're intested I have a stack (from sales conferences) or you can find them on-line. Even a game of Consequences can get people going.

Keep smiling, chick. I know you're concerned, but you love her and ideally this will owrk out as the best day of her life.