Is she getting monthly mitaban dips? There are other treatments that may be gentlier for young dogs such as daily Intercepter tablets. This treatment is effective but can be quite costly, but may be worth it if your dog is having neurological side effects from the dips. Another treatment is a daily dose of Ivermectin, which may be appropriate for your dog. Whatever treatment you choose, skin scrapings must be performed on a monthly basis and treatment must be continued until 2 consecutive negative skin scrapings.
Noni Juice, Royal Canin are fine.
When we rescued our first puppy, Travis, from a dirt road back in 1990, he was nearly starved to death, infested with worms, and both demodex and sarcoptic mange. He hardly had any hair anywhere, and the mange mites had about destroyed his hair follices. Of course, he had the attendant staph infection in his skin from the mites. Travis was about 6 weeks old when we found him, and the only treatment back then was the mitaban dips. For the first few months, he was dipped every 2 weeks at the vet. After that, it was about every month and the vet let us take care of dipping at home. Over time, the need to dip very gradually increased. Travis lived until almost 14 years of age and had a great life, so it was worth all the time and money to keep him healthy. You just have to be very patient in these cases.
It took us over 4 years to finally get the mange under control. From what I understand, most dogs will have these mites in their skin at some point in their lives, but their immune systems can deal with it and they don't show symptoms. Obviously, Travis had some immune issues at work having such a severe case.
I know the mitaban is some strong, and strong-smelling stuff, but you have to keep up with some kind of treatment until these mites are eradicated. Here is a link to a slideshow of my rescued dogs, with the first 3 pictures of Travis. See how he started out, and how he ended up. Absolutely worth it! :-) http://pets.webshots.com/slideshow/562072087XLwpKg