This treatment is being suggested on bases of the information provided. However I would like to examine & investigate the patient  in detail. Control  Hypertension, Diabetes or any other metabolic disorder, if there is  any. Any way it may be tried, --. Dolokind Plus (Mankind) [Aceclofenac100 mg +Paracetamol 350 mg] 1 tab. OD & SOS. X 5 days. --. Caldikind plus  (Mankind) 1 tab OD x 10 days. (You may need help of your local doctor to get these medicines.) --. Fomentation with warm water. Let the part not be exposed to cold air. --. Sleep on a hard bed with soft bedding. --. Use no pillow under the head. --. Avoid painful acts & activities. -- .Do mild exercises for  knees and ankles and hips. --.(Take help of a  physiotherapist). --Do not ignore, let it not become beginning of a major problem. --Do ask for a detailed treatment plan. Kindly make sure, there is no allergy to any of these medicines. --For emergency treatment visit nearest hospital. --Wish you a quick recovery & good health. --I hope, I have solved your problem to your satisfaction.  Dr N C Gupta MS (ortho)

The information that I can gather from what you have mentioned is that your mother probably has osteoarthritis of the knee joints, and since it was not advanced enough, the doctor prescribed medicine and exercises, the possibility is that she may not be doing her exercises properly, also see if she is following instructions of the doctor, and taking medicines regularly and correctly, If her condition show no improvement kindly consult your doctor again and get examined, so that any thing other then osteoarthritis can be ruled out.