[*winter*]

Certainly they do philanthropy events. I'd try to go to as many as possible. Or lunches, dinners, study hours- anywhere there are sober people. See if there's a subset of girls that maybe you don't know well yet who aren't all about partying, and try to get to know them. OTOH if the sorority is small and you've met everyone this may not work. But it never hurts to try to get to know them outside of a party atmosphere. They might be serious students too, just the kind who like to cut loose on weekends.

FWIW, I didn't have a connection to my "pledge mom." I found her to be kind of cold. Is there ANY sister(s) you have a connection to/with that you can talk to about this?