Hi T.,
It's actually not that weird -
I have anxiety issues, and when I am stressed out about things I get a strange sensation in my feet too. I wouldn't really call it itching, but more of like a tingly sensation. If I am wearing shoes and/or socks, I have to take them off because my skin feels like it is crawling when I wear them. It is almost like restless leg syndrome where you cannot really explain the feeling, but you need to move them around. (got that too - didn't go away after pregnancy)
It sounds like it could be similar. I would just keep an eye on it, and if she has a lot of sugar in her diet, I would cut it out completely. I have cut sugar from my diet, and am almost ready to stop taking my anti-anxiety meds because it was actually the sugar causing my anxiety. Sugar, in any form, does terrible, terrible things to the body and in excess can really cause serious health issues. I cannot believe how much better I feel and how much weight I have lost since I gave up sugar.
Sorry for getting sidetracked, but there really could be a correlation.
Good luck and hope she feels better,
L.