Please do name this person, it helps the community!

If your friend paid through paypal, she can file a
complaint with them, and paypal is generally very
good about returning money if possible.

When you fill out the money order, there is a stub
at the top that allows you to get your money back.
 I'm not sure what the requirements or limitations
are, but that is your best recourse.  Was this
seller on eBay?  If so, you can file a claim
through them, but you may not get money back.

I hope this helps, please do let us know more
information!