You should look into the Chicago City chapter. It's a fun and a traditionally YOUNG crowd.

I know this is an oldish thread, but I'd suggest trying out your local alum chapter even if that sister is involved. Even in my much smaller sorority, we had some sister drama, but after we all graduated, a lot of those rifts healed. Would there be any way to switch alumnae chapters in the event that you were still unhappy with your local chapter?