Expect your bunny to be very sleepy and not feeling well for several days. It is painful for bunnies but some handle it better than others. Some girls are fine and eating and some (like my little Bridge bun) are quite lethargic and unwilling to eat on their own. That’s great that she will be given pain meds (some vets don’t). You should have all her fave foods on hand to entice her to eat afterwards as well as some Oxbow Critical Care in case you need to force feed her.
It’s a pretty major surgery so she will def be uncomfortable but most bunnies bounce right back and heal up no problem. While she is at the vet is a good time to thoroughly clean her house, scrub her litterbox, wash any blankets etc. A clean area is important for any incision.
My girl was able to use her litter box. If it has a low side she shouldn’t have a problem. If she has to jump to get in it, you may want to get her one with a lower side. She should be kept from running and jumping for a week.
You’ll need to check the incision 1x day for signs of infection which are redness, swelling, bleeding or oozing. Most bunnies have no problem but my Olivia got an infection between the skin folds (which looked like a little hard bellybutton along the incision). The vet cleared this up with some antibiotics.
You should wait at least a month for her hormones to calm before doing any bonding.
Spaying is very important so rest assured you are making the best decision for your bunny.