It's possible. Fatigue and itchy skin can actually be side effects of mild to moderate food allergies. I had the same kind of thing back before I discovered I had an allergy to wheat. Perhaps she is eating something regularly that is causing her body to suffer. I would definitely try being Primal because it cuts all the stuff that human beings just recently started eating, and if that doesn't do the trick I would go in for some food allergy tests. Nuts and shellfish are also common allergies that could be causing this.
Stumbled into Primal due to food allergies, and subsequent elimination of non-primal foods.
Start Gluten-Free/Soy-Free: December 2012; start weight 158lbs, Ladies size 6
Start Primal: March 2013, start weight 150lbs, Ladies size 6
Current: 132lbs, Ladies size 2
26lbs lost since cutting the crap.