Well at age of 43 she is most likely to have arthritis. But needs to visit personally for clinical examination.

Sir, bow legs can happen due to many reasons like infections eroding the bones, imbalance in the mineral content of the bone, destruction of the cartilage supporting the bone, trauma or improrerly healed fractures,intake of high fluoride content water, sometimes also seen in obese patients.So first enquire about any trauma she has suffered in the past which was neglected,enquire about any infection which has occured in recent time which she has not taken treatment properly, if she is obese kindly advise her to reduce weight if possible consult a dietician, get the fluoride level in your drinking water checked and get it corrected.kindly consult a orthopedician because there are corrective surgeries available to make her comfortable and considering her age suceess rate is good if their is no other contraindications.