Odd Girl Out (floor plan question)

I'm about halfway through Odd Girl Out, and I have a kind of silly question: Does anyone understand how Laura, Beth, and Emily's dorm is set up? I can't figure it out.

Like, their dorm seems to be multiple rooms? Like a suite? Do Laura and Beth share one room, and Emily is in another? But when they all "get home" they seem to be in the same room? And when it's cold Beth and Laura sleep in some other room? Did dorms in the fifties look very different from now?

Thanks for any insight! :)

Oh, it's a sorority house! That helps. If anyone has a clear idea about house layout though, I'd still appreciate it.