Hi in general arthritis is associated with swelling of the lowerlimbs but if shes been on long term medications for rheumatoid arthritis i would suggest to ger her renal (
kidney function tests) paramaeters like S. Urea and S. Creatine to find out if they are normal as long term medication affects the kidneys
Next Steps
Kindly wear appropriate size compression stocking or compression bandage while walking and sitting
Health Tips
Whenever possible keep the legs elevated to prevent dependant swelling