Please take her to a surgeon preferably a vascular surgeon and get guided from there

This treatment is being suggested on bases of the information provided. However  I would like to examine & investigate your mother in detail. Rule out Hypertension, Diabetes or any other metabolic disorder. 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. --. Sleep on a hard bed with soft bedding. --. Keep  no pillow under the head. --. Avoid painful acts & activities. -- .Do mild exercises for knees and ankles and feet. --.(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 Contact your family doctor or visit nearest hospital. --Wish your mother a quick recovery & good health. --I hope, I have solved your problem to your satisfaction.   --Kindly rate the answer. Dr N C Gupta MS (ortho).

How old is your mother? Veins are not responsible for pain.

Please post knee x ray

your mother may be having some age related changes in her knee joint which may be the cause of her pain She will need x ray of knee joint after which you need to meet with an Orthopaedic doctor