Noted the point.
Noted that your sister had papillary cancer
and they have done a thyroidectomy
. Did they remove any lymphnodes
from axilla?? Usualy that is not reuired. But if done, it can cause this swelling.
Other possibility is that of a thrombus inside the veins. I feel you must go to the surgeon and get a vein doppler scan of both hands. If a clot is seen, she will need blood thinners
It is not normal for both hands to swell up after thyroid surgery
. Sometimes if there is bleeding in the operated site which can enlarge and press on the blood vessels in neck and chest region. Please get an ultrasound