hi there, probabely your mother is suffering from type2 diabetes
and it can be controlled with oral tablets and diet and exercise. As your doctor rightly said such symptoms are usually associated with diabetes. See to it that her blood sugars are under controll by doing periodic blood sugar levels and HbA1C
test every three months. Also along with her diabetes medication she should receive supplimental vit B complex. Usually keeping the blood sugar in check will relieve her of much of her symptoms. She can use painkillers sparingly. Also it would be wise to get her kidney
functions checked atleast once in 6 months as kidneys are very frequently involved in diabetics. Take care.