There could be many reasons for development of hypoglycemia
in your mother and it becomes very important to identify the cause behind it,so that necessary steps be taken to prevent its repetition in future.
1... Not taking meals properly and continuing with your anti diabetic drugs
2... Accidental intake of extra dose of anti diabetic drugs
3.. There may be a development of diabetic nephropathy
in the patient resulting in increased amount of available anti diabetic drugs in the blood.
If the cause is diabetic nephropathy,then the diet has to be given very carefully and extra care has to be taken regarding intake of protein and fruit juices ( avoided in chronic kidney
Whatever supplements and diet has o be given,it should be in consultation and consent of treating doctor.
Don't give even any herbal preparations of your own as they can be nephrotoxic.
I hope it helps.