Layla also threw up twice when she first got home from being spayed. I would say the first 2 days she really slept alot and it took her about 5-6 to be back to normal. When we had Riley nuetered he was up and running the next day so I was a little concerned. The vet told me it was normal for the females to recover a little slower as long as she was eating and drinking. But if she continues to vomit I would contact the vet in the morning.