My uncle has two nieces, one by marriage (Beverly) and one biological (me). When I was in the
Adelphean for our version of the Sisters of the Year award, Bev called me for the first time (she's something like 20 years older than I) to say that she was an ADPi, too! Further coincidence: the mother of one of the ADPis on GC went to school with Bev.
It still irks my uncle that his step-granddaughter went to a school without ADPi.