Some rabbits don’t bounce back as quickly from a spay surgery as others may. Some may start eating right away but others do not want to eat and have to be syringe fed. Some rabbits may be more active, while others may not want to move much at all. It’s understandable that she is quiet and that she may be hiding from you. Did the vet give you pain medication to take home with you? Most rabbits will need it for a few days.
Make sure that you have all of her favorite greens and fruit on hand to tempt her to eat. Besides the pain she may have (pain medications may not take it away 100%) she is also experiencing fluctuations in her hormone levels. That can cause a change in her behavior, which should go away when the hormones have leveled off. The whole experience of going to the vet and going through surgery can cause rabbits to act differently, but that should change as she starts to heal. Sit near her, speak to her and pet her, if she wants it. Keep encouraging her to eat, but keep up the syringe feeding if she isn’t eating. Hopefully she will feel better and be back to her old self soon.