One of the first things to do is to make the diet Alkaline. Reduce processed foods, white breads, sugar. Absolutely no soda. Mild exercise like walking. Staying properly hydrated as well. She should consult a nutrition specialist who can guide her towards a proper diet. If she is overweight, then weight reduction as well. A blood sugar that high would signal a look for the cause, not just treating the symptom. Prayers for your wife. 🙏