Hi,
Welcome to HCM,
Your mother is having Diabetes type II and Hypertension her blood sugar is FBS 135mg/dl and PPBS is 185 mg/dl.This medicine is Metformin in slow release formulation this can cause GI disturbances,
Lactic acidosis.Anorexia, nausea, vomiting, diarrhoea, weight loss, flatulence, occasional 
metallic taste, rash, malabsorption of Vit B12.
She is taking for last 1 year so her symptoms are unlikely due to side effects.
 She should visit internal medicine specialist  or 
Endocrinologist to examine and investigate by 
Complete blood count,Kidney function tests,Liver function tests and 
abdominal ultrasonography to find out cause for her symptoms.
 If her blood pressure is not controlled and if required a scan CT or MRI may be warranted to decide further course of action.
Please take care.
Good Luck.
Dr.Akhilesh Dubey M.D.