The most likey cause for symptoms of your mother seem to be due o uncontrolled diabetes
resulting in urinary tract infection
travelling upwards and causing kidney complications which ultimately might have resulted in renal failure.
Ideally your mother should have received injection insulin for control of her blood sugar along with double antibiotic therapy after getting a proper culture and sensitivity test.
She should be admitted in the hospital and treated in totality by a nephrologist
and a diabetologist