At Brooke's Bat Mitzvah.
"Brooke is the nucleus of our family," said dad Howard Greenberg. "What if Brooke holds the secret to aging? We'd like to find out. We'd like to help people. Everybody's here for a reason. Maybe this is why Brooke is here."
Watch Brooke's story on "20/20" FRIDAY at 10 p.m. ET. (Courtesy Greenberg Family)