Hi and welcome to YT
! Glad you found us. Do you have a "onesie" t-shirt - that's what most of us use and it usually works quite well.
It's not uncommon for them to still be sleepy the next day, her body is still under quite a bit of stress. For pain, I always insist upon bringing home pain meds and a pain plan with me from the vet...didn't the vet offer pain meds? For major abdominal surgery such as a spay, I'd insist on having pain meds available for the 1st week. If you don't have them, I'd call the vet and ask for them asap as her pain med injection from the surgery is definitely not potent anymore.