My 2 boys had thier tonsils out at ages 5 and 3. One child hung out on the couch for a couple of days, but the other one was up and running the day after surgery! I'm not so sure about the out of school for a week idea. Maybe other mothers have had that experience. Perhaps they could schedule her surgery for late in the week and then she would have the weekend to recover. She will probably feel so much better after she recovers compared to before the surgery. Both of our boys also had tubes in thier ears at the same time and life was so much better. They could hear once again (they had lost some hearing), thier appetite improved and thier overall attitudes were much better.
If she has a favorite bear, doll or blanket, they will let her take it in to surgery with her. I know she's 9, but it will still be a great comfort to her. We've had a few bears that have gone through surgery. :) They even had thier own arm band.