She will be okay. Cats, unlike dogs, seem to know when it's okay to go back to the normal routine. I've never had one of our cats lick their stitches too much or anything like that. Like people, different cats have different reactions to general anesthesia. Some bounce back really quickly, and others are groggy for a while. When you bring her home, confine her to a room with her litterbox, her food and water, and a safe, comfy place to sleep (a box on its side with a snuggly blanket in it, maybe, or a corner of a closet where she can curl up). She will come out when she's ready. I've had cats come right out of the carrier and be ready to resume their normal activities, and I've had others who hide in the closet for a day or two. As long as the cat is using the litterbox and eating/drinking, they are fine.
Good for you for getting your kitten spayed!