Hi Corn, usually is the protective & defense reaction of the body at the site of local pressure. It is normally due to the hard footwear, which, at a particular spot is giving more pressure on the underlying tissue. Ask her to wear footwear which has soft soles & light in weight. Better still if she wears shoe-like footwear. If over weight, she had to reduce her weight. If the corn is painful & troublesome, you can bring her to my clinic. I can cure the problem Regards