[Dionysus]

Ditto what others said.

Also, in a round about way, find out WHY she's doing it. I would be very curious to find out why. Could be something like jealously or spite, but she could see something that you all don't see in yourselves. If it is the last, that needs to be taken care of by your chapter too. The fact that she's in good standing with her chapter and say things like "XYZ Chapter is an embarsement to our entire sorority." "XYZ Chapter is the worst chapter and nationals made a mistake in opening it." it sounds like there's a possibility that she may have had an bad experience with your chapter or someone in it.

PS-nice name or nickname. (and no kids, i am not this person, lol)