I guess that's what I'll do.  Somehow that situation doesn't feel satisfactory to me at all.  Like it's ok for me to sleep at her house, but it's not ok for her to sleep at my house.  If that's my only option, then I guess I would take it, but it still feels horribly insulting to me.  Like, it's almost worth it for her to never come than for her to stay somewhere else like a stranger.  Everyone's family uses my guest room, but my own won't?  My guest room has hosted my roommate's mom (from Sacramento) three times, my neighbor's mom (from Palm Springs) countless times, and numerous other visitors, who all thanked us and said it was a great place to stay and we were so gracious for letting them use the room, but my own sister won't stay there?  To me, that's weird and wrong.
I don't want to be uncompromising about it, that's just how I feel about it though.