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In my rehabilitation work (I work with pitbulls with aggression/fear issues), I've found two over the counter medications that really do seem to do the trick, but without any of the nasty side effects.
Melantonin is an over-the-counter drug that can be used to treat some anxiety issues in dogs. The dose you would give would be up to 3 mg given orally whenever necessary up to every 8 hours. More information can be found here: http://www.petplace.com/drug-library/melatonin-melatonex/page1.aspx , which includes risks, warning signs to watch out for and other bits of useful information.
Try a DAP collar. These are collars that are impregnated with a man-made version of the dog appeasing pheromone, which is a pheromone that nursing bitches give off to their pups to help them feel calm and secure. It's something that humans can't smell, but it has an amazing effect on dogs with anxiety and other issues. Although you can find them at your vet's office..you can also find them online at places like Amazon.com and Ebay for much cheaper. Just make sure they're DAP brand, as they seem to work better than some other versions.
I generally start with the collar and then add in the Melatonin if I don't see an improvement within a few days.
If those don't work, you may want to talk to your vet about trying something like Acepromazine or Clomicalm. Both of these are sedatives which provide the calming effects, but of course will also make her very groggy, which I find to be a down side when trying to rehabilitate a dog with behavioral issues (you can't train a sleeping dog).
I hope this helps.