I have been to Alumnae Panhellenic events in both Miami and Ft. Lauderdale.
If your group is anything like these groups, then prepare to be one of the youngest members there.
Even when I went to the Ft. Laud Panhel luncheon this past spring (to support the president, who is a KD), I was one of the younger members!
But it's inspiring to see all these women (from different sororities & different schools) getting together at their age to promote greek life.