Just talk to her ,let her decide what she want..that the best you can do ..

Sometimes when thrown together 24 hours a day on a trip etc the true dynamics of friends/relationships become apparent.. You have already committed to your rude friend.. To reverse out of this could cause problems.. You seem protective towards your anxious friend. See how the cards fall.. Try not to assume too much responsibility for other people, worry more about yourself for the moment. See how it pans out..

Talk it out as a group before hand. And remember you are all adults. You don’t have to like each other. You just have to get along. Adults should be able to do that.

well let her decide