I read a book when I was in I think 4th or 5th grade and I am 30 now. I do not know when it was written, but I read it around the same time that "The Giver" came out which was 1993.
A girl woke up either on a space station or space ship (I think station) to find that things were drastically different. She has a little sterile room she lives in. At a certain time of day I think the doors automatically open. As if there is someone controlling everything, but she isn't sure who?
The main idea I remember is that everything seems to be run on auto. Everyone knows where to go and when. They all have assigned duties and everything is sterile. I think the food was in pill form or something similar to that. She describes the bathroom situation in detail and sadly that is the main thing I remember. She was very taken by surprise at the restroom that had no toilet paper and instead automatically shot out sterile cleaning fluid. I guess it was somewhat like a bidet.
I know this isn't much to go on. Even if some of the details aren't quite the same please give me any ideas you have! I could be remembering something incorrectly at this point. Trying to remember this book has been driving me crazy for darn close to a decade.