Let her watch TV at the surgical place. Let her color, play toys, play on your laptop/cell phone/tablet, be cranky, etc...tell her the doc said she can't have anything and you have to do what the doc says. Don't make it "I" said anything. This is an easy one to let the hit go to someone else. She won't be mad at you.
There was an infant one time that had to have surgery and their appointment was at 9 or 10 in the morning. The doc had an emergency surgery and didn't get that baby back until after lunch. We all tried to entertain it so the parents wouldn't be so stressed. We all took turns making faces at her and trying to alleviate the stress as best as we could.
In these cases the little people should always go first unless the person in front of them is an emergency case. I'm so sorry you are going to have this happen.
Just know that she should wake up ready to go! Every time we've done the general anesthesia for dental work the kids were bouncing off the recovery bed wanting to go eat! They were rested and happy and hungry!!!
There are usually very few side effects to the general anesthesia. Gas, on the other hand, is often a nightmarish event for kids. They wake up and the gas lingers and lingers. Until their lungs clear out every little bit they are hallucinating and screaming banshees. The surgical center told us that's why they have recovery against the back wall as far as possible away from the front, they also have a back door for parents to take the kids out.
Gas was what the ear doc used to do tubes in our boys ears. He woke up screaming and grabbing on to us and begging us to not let him go. It was heart wrenching. They told us over half the kids wake up like this.
General anesthesia is awesome!!! I would never do gas if at all possible ever again.
Good luck with the kiddo.