Impossible to advise as it is not even possible to see the item or feedback left. It would also have helped to know whether if the buyer opened a Not As Described case, whether your wife dealt with it or the buyer had to ask ebay to step in.
Appealing against this sort of situation just produces the standard reply " Well that is the buyers opinion of the transaction".The fact that buyers can't be bothered to read doesn't seem to matter.
You could try speaking to ebay, but I would not hold out much hope as CS are about as much use as the robots.
There is the option to leave follow up feedback, but be careful what is said.
