Both of my boys have had theirs out. Honestly it isn't bad at all! She'll be fine!
We left the hospital just hours after the surgery. Before you leave the hospital, they want you to urinate. And with my oldest, he didn't want to so that kept us in the hospital until he stopped being stubborn. Performance anxiety or something. LOL My youngest son's surgery was a breeze, however his stomach didn't like the pain meds at home so we had to get a prescription for phenergen. I HIGHLY recommend asking for a written prescription of phenergen just in case there are issues with her throwing up the pain meds. They are a suppository which of course nobody likes, but they work and the throwing up stops so the meds can work. After 2 days of the heavy duty pain meds, we switched to alternating tylenol and motrin every 2-3 hours. (check with your doctor, LOL) I'd expect she'll want to be lying on her bed or couch for nearly a week, not really sleeping but just too weary to be doing much else.
As for foods, some people say to stay away from dairy after the surgery because it increases phlegm production, but I was just happy to get the boys to eat. I'd recommend mac & cheese, apple sauce, pudding, jello, popsicles, and other soft things. Popsicles/Otter Pops were really pushed by the doctor because it gives extra hydration, no dairy, and is numbing to the throat.
I'd also recommend getting some movies she'd like to watch for that week, and books and such to chase away the boredom of recovery.
Good luck and quick healing to her!