Actually, in New York you can be required to support your child until age 21 – but once he or she is 18, you cannot tell him or her what to do. Crazy, no?
I can say that I called a butcher upstate, an hour from me (the closest), and he said Israel Mayer Steinberg (who is, indeed, the Cup-K) certified him, AND SOLD HIM HIS MEAT! (Can you say conflict of interest?) When someone in my synagogue asked about another shop certified by Rabbi Steinberg, the authority asked said, “Better he should buy his meat in Monsey.” That’s a polite way of saying, “I wouldn’t.”