You need to get a veterinary evaluation first to rule out medical causes for her nervousness. Most veterinarians are not comfortable or well versed in behavior, but if your veterinarian is, great! You need a diagnosis and treatment plan.
If your veterinarian is not, then look for a board-certified veterinary behaviorist (http://www.dacvb.org/resources/find/) to consult, a certified animal behaviorist (http://www.animalbehavior.org/ABSAppliedBehavior/c... or reward-based professional trainer with experience in behavior modification, including anxiety - preferably a clicker trainer.
Oftentimes veterinary behaviorists will consult directly with your local veterinarian via the phone to develop a diagnosis and treatment plan.
The treatment plan will include an individualized behavior modification plan that will include procedures such as systematic desensitization as well as a unique combination of therapeutic modalities for your pet. It should be based on a thorough behavioral assessment.
Some modalities that you can implement in the meantime include: 1) The Anxiety Wrap (www.anxietywrap.com), and 2) Through A Dog's Ear music to calm canines (http://throughadogsear.com/).
Please see my hub about the different pressure wraps available for calming pets that are on the market. In my practice I have had 100% success with The Anxiety Wrap: http://dubuquedogtrainer.hubpages.com/hub/dog_anxi...
There are other things worth trying, but seek the guidance of a professional - for example, L-tryptophan (http://www.ehow.com/facts_6057289_l_tryptophan-dog... Composure, D.A.P. (Dog Appeasing Pheromone) and Rescue Remedy.