Few of the many causes of swelling if wrist and legs can be:
1) Heart diseases
2)
Kidney diseases
3)
Thyroid disorders
4) Malnutrition/Hypoproteinemia.
5) Autoimmune disorders like Rheumatoid arthritis and many more.
Next Steps
She will need thorough workup with consultation from General medicine consultant.
Health Tips
Do not take it lightly. Try to consult physician at the earliest for the best result. Delay in consultation will lead to poor outcome.
Take care.