I've never heard vet using staples for spay. It's usually with stitches, and many vets use resolvable stitches that will be absorbed by the body over time.
Healing time is quite fast. I got both my girls spayed at 6 1/2 month old. The vet kept them for half day after operation. The first day when Metoo came home, she didn't look in good shape because of the anesthesia. She slept the whole day, but then bounce back the next day. Meatball doesn't even have that one "down" day. The wound will fully heal after about 10 days if well taken cared of.
Don't worry too much, your girl will be fine. Just make sure the wound doesn't get wet/dirty (you can use iodine alchole to gently wipe the wound for the first couple of days). My vet encourages my cats to be active after surgery, so the internal organs won't "stick". Cat skin are very elastive, so jumping/running won't damage the stitches. But if you have another cat at home, do keep an eye on them and avoid rough playing.