I haven't had that happen to me but I did do it with one of my customers - wasn't a big thing though like a sewing machine - once he sent confirmation that he returned the item i sent his out. i would contact eBay and insist that she honor her deal; she has an obligation to complete the sale. If she doesn't, its a mark against her and as a long time ebayer (10 years), I know it important to keep customers happy. Good luck!