What are you feeding? Try putting her on a raw diet no grains and not all the preservatives added. We are also finding dogs with allergies to things like chicken for example. Search raw feeding online a lot less mess in the yard and it breaks down quicker better for teeth, ears and coat you feed less has been most peoples experiences.
To add to this, we've been told that the binders used in dry dog food are the cause of almost all allergy issues in dogs. Having said that, we've searched all over to find the best dry dog food that we could find. Munster freeze dries their dog food and since using it, we have seriously reduced our itching and allergy issues.
https://muenstermilling.com/
With 6 dogs, and 3 of them show dogs, we want to feed them the very best food possible. Some do not like chicken, others prefer raw, some get canned sardines or salmon. We want them to eat, and for them to be healthy, but also to have excellent muscle mass, movement and beautiful coats.
We feed raw to all of them from time to time, but one of them gets raw almost daily. My wife drives to a local grocery store to get it from them. They have a refrigerated truck that parks there and everyone goes there to get it from them on certain days of the week.
Texas Tripe
Most of our food is made in a crock pot. Beef, chicken and pork with sweet potatoes, green beans and sometimes something else like carrots. I've accidentally eaten it and it's very good!!!! My wife put it on the wrong shelf, in a small container, and I thought it was leftovers.
Just like people, dogs get tired of the same thing everyday, and there is a noticeable result when you change it up from time to time, and offer them something different. But they are also picky eaters if they are not starving, and you can tell by how they react to their food.