Welcome to HCM,
Your mother is diabetic and on oral hypoglycaemic drugs, I presume she must be having diabetes
for few years now,her blood sugar is not controlled at all.
Please visit a good Physician or Endocrinologist
and if there is need please hospitalize her for control of diabetes as there is secondary failure of oral drugs she will need to control blood sugar with Insulin
injection therapy.Just increasing the dose or changing oral drug will not help in such case.Yes it is possible to use insulin and oral drug simultaneously to have good result.
If she is not taking care of diet she should take diet as advised and investigate for presence of any infection.
Once her sugar is controlled then she must walk daily to increase physical activity.
There are very good Basal insulin and pre mixed insulin which can be prescribed to her, she can also do a carbohydrate
count in diet and adjust dose of insulin accordingly.