Make sure they give you pain meds to take home, usually meloxicam suspension. Keep her warm, as anesthesia will lower their body temp. Keep encouraging her to eat. With my buns, their usual leafy greens were the first thing they would eat. If your bun isn't eating or not eating much by morning, give your vet a call as you will probably need to start syringe feeding. I don't usually wait til then though, as I get nervous about them not eating that night and will start to syringe feed if they haven't eaten anything at all. Keep a close eye on the incision and if your bun seems too interested in grooming the area, as you don't want any chewing of the incision going on. And restrict her area and activity for at least 7-10 days, as this is an invasive surgery and you don't want her getting too active and pulling any sutures open before they have had a chance to heal.
Most of the time there aren't any issues and the bun is back to their usual self in no time, but these are just some things that could possibly go wrong and to keep an eye on.