Cowgirl Interlude (Bonanza Jellybean)She is lying on the family sofa in flannel pajamas. There is Kansas City mud on the tips and heels of her boots, boots that have yet to savor real manure. Fourteen, she knows she ought to remove her boots, yet she refuses. A Maverick rerun is on TV; she is eating beef jerky, occasionally slurping. On her upper stomach, where her pajama top has ridden up, is a small deep scar. She tells everyone, including her school nurse, that it was made by a silver bullet. Whatever the origin of the extra hole in her belly, there are unmistakable signs of gunfire int he woodwork by the closet door. It was there that she once shot up one half of an old pair of sneakers. "Self-defense," she pleaded, when her parents complained. "It was a [sic] out-law tennis shoe. Billy the Ked.