I'm crap at this sort of situation as well. I'm not particularly fond of confrontation so this is probably what I would do in theory but I think in reality there is a fair chance I'd just head for a different train or hope fervently that the situation resolved itself!

I would sit down with the others, or whoever you perceive the ringleader (if there is such a thing) to be & put it quite simply as you have in your post - someone needs to spell it out to Betty and do it soon.

I think Betty being such an obnoxious person is a bit beside the point - as someone else said, you need to be true to who you are & how you want to behave and stick to that. If the other girls can't work with that, then maybe catch ups outside catching the train are still ok but maybe not getting the train itself.



Good luck!