Aww, I know how nervous I was with Billi. I'd never experienced it before, but I learned a lot!
She'll probably be really out of it for at least a few hours after you pick her up. She might not want to eat, either. Just give her a comfy and quiet place to rest. It's a major surgery, so you'll really have to keep her from moving around a lot- running, jumping, etc. It'll be really hard the next couple of days when she's alert and wants to play again. Just keep her calm and from running. Make sure she leaves her stitches alone... She'll be fine.
Oh and you'll be fine too!
