Welcome to HCM,
Your mother is suffering from Diabetes Type II, Hypertension
If she is keeping low blood sugar
level then you should report to treating doctor and yes as she is taking three anti diabetic drugs dose or one of the may be removed but you can do so only after consulting your treating doctor/Endocrinologist
One more thing we need to check for her kidney function because if kidney function is deranged blood sugar may go low in case of diabetes.
You should check he FBS,PPBS,HbA1c and Blood Urea and Serum creatinine
and urine for albumin.
Please continue to take medicines as advised please do not change dose yourself.