My daughter’s story is no longer novel. Stories like it are occurring in your state, your town, and perhaps even on your street. Gender dysphoria—the incongruence between the mind and the body—moves stealthily and quickly to invade girls and boys alike. But this isn’t a cautionary tale. It’s a warning. My daughter was an ultrafeminine girl since birth. She insisted that her room be painted pink, and she refused to wear anything but dresses until third grade. She avoided her older brother’s toys and sports, choosing tea sets and Shopkins, a series of tiny, collectible toys. Her favorite activity was...