I would suggest.. You check with1) renal function test in Lab..if there renal problem also there may be chance of oedema in the ankle and legs.. Because of sodium retention..
2)check with blood pressure,
3)make sure about body wt as she should not over weight
Next Steps
if there is no significant change consult near doctors for examination
Health Tips
avoid salt in food till reduction of swelling in the feet.
leg should be kept elevated while sleeping and sitting