Sorry I'm not an experienced owner so can't help, but have you tried doing a search for any threads with the same symptoms?
Is the bunny floppy? Has she eaten and drank normally today? Is she going to the toilet ok? If she hasn't I would get her back to the vets, or possibly a more bunny Davy one.
Sorry I can't be of much help, try and keep her warm. Someone should be along with better advice in the morning.