I'm so sorry to hear she will need surgery.
But it sounds like it's for the best. So glad you took her in, she is lucky to have you as her mommy.
I know how terrible it is to leave them overnight. I think I maybe slept like 4 hours when Jackson was in the hospital overnight. I just kept thinking something would go wrong, or he'd be scared and escape, or they'd walk him on his collar (which was loose so he'd slip out of). I called the vet like two hours after I left and told them about the thing with the collar, LOL. I was sooo paranoid. But all was well and fine and he came home and was super happy to see me.
Good luck during recovery, I know that will be hard too.