I think having a member who was strictly interested in an organization for sisterhood, philanthropy, leadership opportunities amongst women her panhellenic community, and a lifelong alumnae membership would be....EXACTLY why most of our organizations were founded!
I challenge anyone to bring up a group of founders who said "Hey ladies, lets start a group of our own so we can throw keggers with drunk guys!"
While granted, I am not in Texas, and I don't know your school, I can tell you that in my own chapter (which was certainly know for being pretty social) there were always sisters who did not drink, and many who were not into the party scene. They were very involved with all other aspects of the chapter, and they were very much respected for their beliefs.