she takes the non-synthetic. What are nutritional thyroid co-factors?
Various other glandular extracts. See a supplement called "Thyroplex", developed by Dr. Jonathon Wright. Sometimes the thyroid isn't the only thing not working correctly. If she hasn't, she probably ought to see an endocrinologist.
Wright was of the opinion the it was sometimes the case that the function of the support organs wasn't depressed enough to actually reach the level termed "disease" by today's standards, but they were under-performing sufficiently to screw things up.