I purchase a lot of items on ebay for the sole purpose of reselling it for profit. I have two accounts one for selling and one for buying, this way the people I sell to can't see what I purchased the item for.
I have had people do it to me as well, that is just ebay.
lolaluvsu, I understand your frustration. You can't stop her from selling the shoes - but I would message the seller and tell her not to use your description.