Hugs.
I know this is not the same type of surgery, but when my daughter was 7, she had surgery for a Hernia. We all met with the Pediatric Surgeon with her, we explained to her about what it is etc. And then she had her surgery and she was a real Champ about it.
This all happened in the span of 2 days mind you. She was having pain and her Hernia was not going well, thus she had to have the surgery. Quickly.
Her recovery was fine. Got pain meds for her if needed. And she recovered at home fine too. BUT we also told her Teacher, about what she can or cannot do, per her physical activity, for over 1 month, per the healing of her incision, which of course is internally as well, not just the surface. And because we explained to the Teacher about Doctor instructions, she was fine in school too. AND her Teacher, nicely explained to the whole class, about how to "help" my daughter as needed. Because she could not carry anything etc.
At home, well there was the tv, and computer too.
And just keeping her company and anything else, she needed.
But even at 7 years old, her attitude about it all, was great. She heeded to her body, and would tell us if she hurt or was uncomfortable etc. We told her to TELL US, anything about her body or pain, so that we could help her.
Go by your daughter's cues. Talk with her, so she will feel assured.
And its okay to be scared. My daughter was too... BUT, the Pediatric surgeon actually let me into the operating room, and so I could hold her hand as she was sedated and put under general anesthesia. Then, I had to leave. But all of this was explained, to my daughter. So she knew what was to occur, and it helped her feel, less scared.
All the best.
**VERY IMPORTANT IS: the hospital and Doctor, SHOULD be sending you home with some papers about after care, and what to do or not, once at home. AND call the Doc/Surgeon, if you have questions. They will also explain or should explain, after care for her, while you are still at the hospital after the surgery.