Something makes me think that one of Phread's sons turned out to be a friend of Dorothy. I don't remember the details of how he was expelled from the family, removed from all family reports and even erased from the pages of the family bible. I wasn't able to find what I'd consider to be a credible reference to it, but since the largest source of their new members is by generating family members, chances are high that they'd eventually get at least one of us. According to CNN, as of March, 2006, he has 13 children, 54 grandchildren, and 7 great-grandchildren, and the Anti-Defamation site says the church has 71 members (January 2008). 3 of his children are "estranged", so the math looks pretty simple, until you consider spouses.
Anyway, here's another site that has some interesting things to say: hXXp://www.splcenter.org/intel/intelreport/article.jsp?sid=185
Edit: live link removed