LW, have you taught her how to clean, or have you just said 'go clean your room' and expected her to do it?
I didn't have much stuff, but I struggled to keep my room tidy - we had a no food upstairs rule, but I can remember getting hit for dropping my school uniform on the floor, instead of hanging it up. No one ever came to see me at my home, friends-wise, so I didn't care much.