we have tried everything to do with flees that doesn't seem to be the problem could she just be genuinely itchy?.

which type of flea treatments are you using? The shop bought ones like bob martin aren't always enough. frontline combo is a good one.

She could also be allergic to her food. When I first brought Baxter home he kept biting his back leg and scratching his ears. I changed his food from purina to iams and within 3 days he was fine.

another possibility is mange.

It's probably a good idea to take her to the vet but you could try changeing her food for a few days first. Expect a runny tummy though as pups are hyper sensitive to a change in diet.

Some times even after fleas have been eradicated an itch scratch cycle can have been set up or the dog could be allergic to fleas, food or environment. The only real answer is to go to the vet and get some help for the animal.

Oh and yorkiegal is right many of the over the counter treatments are not at all efficient I don't know how they get away with selling them really.