A cat may hide or tuck themselves away and a dog may want more attention that usual. Most pets recover from their spay surgery very quickly and seem like their old selves within a few days.
After bringing her home, you'll want to provide your pet with a quiet area where she can rest. Some pets will be up for a snack within a few hours, some won't have much appetite for up to a full day; both are perfectly normal. If your cat or dog does seem hungry, start with a small portion, about half the size of a normal meal, and see how she handles it. Fresh, cold water should be easily within her reach; staying hydrated will help your pet recover from the anesthesia and avoid nausea when she's up and moving.
Prevent your pet from jumping as much as you can. Remember, she has deep tissue that is healing, which can take up to 3 or 4 weeks. Her incision area will need checked daily for the next week and you'll need to keep her from licking or biting the wound. During the first week, you'll want to avoid baths and any play groups. Until the incision closes, you may also want to swap out your cat's litter for shredded paper.
It may help to break up post spay surgery care into daily, and weekly tasks.