Is she having 1 leg or 2 legs done?
Get a tiny baby blanket to use a sling to wrap under her belly to help her stand up to do potty.
When you finally get her home, check her butt
I know that sounds odd, but the 2nd time Roxy had her LP surgery, she was making a ting cry sound the whole car ride home. I was crying just listening to her, b/c I felt so bad that she had been in pain. Well, it turns out that at some point during her hospital stay she must have had really soft poop, and NO ONE cleaned her hinny. It was so raw and red, I had to buy Butt Paste for babies to help it heal. But that's why she was crying b/c her hinny hurt.
Best of Luck