OP - I agree with everyone else who has said this is a pretty heavy thing to bring up during recruitment. "I've heard of your philanthropy and it seems like they do really great things" is as much as I would say about it.
There's also (although I hope no one is as cynical as me) the chance that if you brought up that this issue affected you personally, members might think you were trying to play on their sympathies and get an "in" to the group - especially if it's one of the more popular sororities at your school. I do not think that's the case at all, but then again I'm not a sorority member who's been on her feet for 10 hours meeting 100s of PNMs. You tend to get a little frazzled.
Good luck sweetie
