She recently made history as the first transgender person to be featured on the cover of National Geographic . A chat with Avery Jackson and her mom. At the National September 11 Memorial & Museum , there's a giant wall with the portraits of all the people who were killed in the World Trade Center terrorist attacks. Until recently, though, seven people weren't included. Hear how the photos of five of them were located in a cave in Lee's Summit. Guests: Avery Jackson, nine-year-old