It's likely she's still a little "off" from the medication. Usually they are administered painkillers that stay in their systems a few days. After Tysa got spayed, she stared at walls and made weird sounds, slept a lot. Acted quite strange for a few days, but got better soon enough.

You could call your vet and explain exactly what's going on, they'll have a better idea of if it's something to worry about. I personally think it's just to do with the drugs, but never a bad idea to discuss it with your vet.