Would you think this rude?

I was going through a tough time with my boyfriend and my girlfriend invited me to stay at her house, a few states away, saying that time away from the situation would be good. I asked her if Id have a place to sleep and she said of course and not to worry about it. Well, turned out they were in the middle of converting their basement and right now its just the wood frame and cement floors. They bought an air mattress and expect me to sleep on the floor. Its a tiny air mattress, so small that the one night I did sleep on it, it was dificult because I could feel the cold from the cement. Not just that, but the basement still has that dirty, dusty musty smell even after sweeping and washing it down.... So Ive been sleeping on the couch and I can tell it bothers her. What gets me, is she has 4 large dogs- two huskies, a bull dog, and a German Shepard that pretty much have free reign on the house and couches. I can tell shes tense about me sleeping on the couches, what should I say? I plan on staying here for two more months!