I did a google search and found that she is a member of Pi Beta Phi and that she wrote an article about her sorority for Playboy. I couldn't find the article though.
I aboslutely love her columns in Elle!
ETA: Here's the link to all the articles she's written (at least the ones that are on her site) I skimmed around and didn't find one about sororities, but maybe the article you are talking about is part of one of her books
http://www.ejeanlive.com/esqarch.htm
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