Emily Rapp was born with a congenital defect that required, at the age of four, that her left foot be amputated. By the time she was eight she'd had dozens of operations, had lost most of her leg, from just above the knee, and had become the smiling, indefatigable "poster child" for the March of Dimes. For years she made appearances at church suppers and rodeos, giving pep talks about how normal and happy she was. All the while she was learning to...