T.L.
My daughther also had an abdominal hernia and had to have surgery. She was younger than your daughter, only 13 months at the time of surgery.
I was worried sick about the anesthesia and how she would tolerate coming out of it.
She did amazing, from the time they took her away, until she stared to come out of it was about 35 min., she was sleepy but that was all. We took her home and she rested for a couple hours, and then was up and around as if nothing had happened- running and dancing that same night.
The hardest part was waiting and worring beforehand.
The one thing I would suggest is that you have the surgery done the very first thing in the morning, as they are not allowed to eat or drink anything for a while before the procedure.
Good luck, it will be harder on you than on her.