Your mother is having swelling on tne body due to water retention caused by failing kidneys.
You should consult a nephrologist
as she requires a diuretic
to pass the accumulated water.
Pain killers are nephrotoxic and so medicines like proxyvon should not be given.
For pain either paracetamol
or nimuselide is advised,as they are kidney friendly.
Consult a nephrologist as early as possible.