UPDATE: We just got back from the vet. They said it was healing crooked so they took the splint off and she just has it bandaged. She should be able to bend her leg. The buyer is getting a little impatient, they want to pick her up as soon as possible. I'm not sure what to tell them and I'm not sure if she's going to make a full recovery has anyone experienced this? will it heal?
Did the vet seem confident that it would heal ok just bandaged?
Do you know what the bones looked like on the xray? If the bones are touching they will probably mend if the bunny is kept still and quiet, because its young and bones still growing mend quickly. But if the bones are broken completely apart, not touching they might not mend.