I hope you've also pointed out to her, she needs to be very careful when pursuing her revenge - if it backfires, she could wind up being seen as a bunny boiling b*tch & all the sympathy will go to him, the fact that her bad behaviour has occurred after she was dumped will probably be forgotten as well.
She needs to suck it up, dress to the nines every time & be nice as pie to his face no matter how much it kills her to do so. Any thought of revenge needs to be beaten down.
Buy her an anatomically correct voodoo doll & a sharp vegetable knife or email her this virtual one
http://www.virtual-design.com/demos/voodoodoll /voodoo.asp?section=demo&subsection=voodoo