Vanessa and JR Ford didn't know their youngest child was a girl until she told them on her fourth birthday. "Mom, I'm not a boy," she said. "I'm a girl in my heart and in my brain." As the parents of a transgender daughter, Vanessa and JR are at the epicenter of today's changing terrain when it comes to gender. The Fords are just one of the families featured in Katie's new documentary, Gender Revolution: A Journey With Katie Couric. In this companion podcast, Katie and Brian dive deep with the Fords and two others featured in Gender Revolution: Georgiann Davis, a sociologist and intersex activist, and Dr. Joshua Safer, who runs the Center for Transgender Medicine and Surgery at Boston Medical Center.