I think to help make as stressfree as possible use a carrier for her. Bring a water bottle and attachit to the cage. I always bring Apollo's hay and pellets too. That waythe carrier has some familar smells from home and it usually has acalming effect.
It may help to do a trial run first. That way you know how sheis going to react. Take the carrier with her in it and drive around theblock. Try a couple short drives and increase the time she is in thecar. Most rabbits are fine in the care. Apollo loves going for carrides.
When does she go to the vet? Do you have a few days to prepare? I hope so. How was she on the car ride home?
Tina