How do I handle this rooming situation?

So my school is going on a trip to Florida in a few weeks. When we picked roommates I roomed with a friend (we'll call her m) and this girl I absolutely can't stand (we'll call her g), but she was a friend of m so I didn't really mind. But I am done with this girls crap she's already arguing on how she needs a bed and refuses so swap for the couch bed every other night and how she needs a personal nightstand and all the time she wants in bathroom. G expects us to basically give her princess treatment (I won't of course) but this'll be a hard week with her. Plus her and I are officially fighting over a guy. Now m is starting to pick up her conceited behavior and started believing she's better than everyone, so we aren't on good terms either. My chaperone group is great, but I'm not sure how I'm gonna get through the week without stabbing someone. Oh and the guy we both are after is in the chaperone group. I can't switch rooms and I already plan on taking the couch bed which is in a separate area from the main bedroom. What else can I do besides bring a freaking knife?