Painful stump warrants a few things. Somebody should help her check the stump- how's the temperature of the surface, is there redness
, is there any blister/ tenderness, is it getting discoloured bluish, is the prosthesis
fitting well- just snugly and not tightly around the stump, does she have fever, does she have pin-prick sensation, tingling
or just plain pain ...please make sure you rule out all these possibilities and if you notice that something is certainly present then take her to her surgeon for the further care. Otherwise a Diabetologist
can suggest medications for the neuropathic pain
if none of the above symptoms exist at the stump other than pain. Wish you good luck.