How old is your mom ? If she is fortyplus and there are other children also,she could be suffering from some deficiency disease like osteoporosis
or else some arthritic problem in hip,spine etc. History of prolonged sore throat
points to some infective pathology as well.For proper evaluation,get a thrat swab culture for bacteriological study and suitable antibiotic.Consult orthopedic surgeon with X ray of pelvis with both hips AP And Lateral views,bone densitometry-Dexascan,arthritis profile tests,CBC,Serum calcium,ionic calcium,ESR,CRP etc.Also urine culture for infection of urinary tract
for kidney,For all this ,she must have a systematic follow up with doctors,physicians.