Coy Mathis, 6, left, with her brother, Max Mathis, 6. Not pictured is the third triplet, Lily. Photo courtesy of the Mathis family
In this Monday, Feb. 25, 2013, photo, Coy Mathis, left, plays with her sister Auri, at their home in Fountain, Colo. Coy has been diagnosed with Gender Identity Disorder. Biologically, Coy, 6, is a boy, but to her family members and the world, Coy is a transgender girl. (AP Photo/Brennan Linsley)