Is the vet in Riverdale a derm - I hope so, not to be a pest, but I just think a specialist will get you on track right away here. Skin issues are *tough* (as you can see) - I've been there too.
On the food - chicken and beef aren't bad, per se, it's just that these are so commonly fed, therefore, high on the allergen scale. At this point, you don't know she has a food allergy, however, assuming she has SOME kind of allergy - it is true that allergy dogs (in general) do better on low-allergen foods. This is because once the immune system is overstimulated, it becomes more vulnerable to *all* more higher-potential allergen ingredients.
So, I would also avoid turkey and lamb - bc if she has been fed mass-market kibbles, and you look at the ingredients, it's likely that both turkey and lamb have been in her foods.
What you're trying to find is a "novel" protein source that she has NOT yet eaten before in her LIFE - such as: venison, rabbit, kangaroo, buffalo, fish, etcetera. That she doesn't like Natural Balance is a bummer...though I'm not a big NB fan bc it contains flax
, which I don't think is a good idea for allergy dogs.
Are you willing to cook for her? Has she had fish before? I don't normally do this bc I think homemade diets should be supported by a nutritionist, however, bc of the condition of your baby and if you're seeing a Derm shortly - I will share a fish recipe via PM that you can use temporarily, which I got from a nutritionist for my Marcel when he was having issues. It's considered hypoallergenic and has 1 protein, 1 carb source - which is what you're looking for (and veggie & basic supps.). Please let me know...