This doesn't sound all that unusual for the evening following the op. Some dogs suffer more from the anaesthetic than others. Some make more of a fuss than others. I would be not be getting too concerned yet, but absolutely call the vet if you're unsure as we can't see her.
That sounds very normal - they often don't eat until the next day so you'll probably see an improvement tomorrow and over the weekend. I usually find it harder when they're feeling better and I'm worried about them jumping around or getting at their stitches - but it soon passes
Yes it depends how they affect them. I have had two who behaved as normal but one like yours (she would have been 18 months -2) and she was very sleepy, wet herself etc But she was like it after any sensation following I found. It's just how they are
I am sure she is fine, hut call your vet if you are worried as soicypear says. She's lucky to have you x
Shaky is really normal, it is the effect of the anaesthetic wearing off. Sounds as though she is recovering well, they do seem to bounce back astonishingly quickly. My pup is five months and I'm dreading the spaying, I haven't had a bitch before, but my last dog had several surgeries. How old is your dog? Wishing her a speedy recovery.