As a leader of an organization with a charter, I can see both sides of this issue.
I lead a Cub Scout pack. Our charter states that we are made up of home schooled students only. A mom called and told us she home schooled one kid and not the other (don't ask my opinion on that) She wanted to know if we would allow the non-home schooled kid to join as well. We discussed it for a long time and declined to accept the boy because it would dilute our charter for the next time a question arose. FWIW, she told us that she would go along with either decision.
Alternate universe ping