Tournament badminton, because it requires the eye-muscle coordination of a falcon and the stamina of a plow horse, is not a child's game. Yet the Pritula children of Detroit have made winning badminton tournaments a family affair. Thirteen-year-old Sharon (center) is currently the 18-and-under national singles and doubles champion. Bobby, Sharon's twin brother, holds two national boys' titles and, with his younger brother Jimmy, reigns as the under-13 doubles champion. Together they have amassed 148 trophies. Little Suzie, who is just learning the game, did not win her woolly dog. Father Vic took up badminton after an injury forced him to give up amateur hockey. Soon he and his wife Norma were winning tournaments. Three years ago Norma Pritula, then the defending Michigan champion, came up against Sharon in the state tournament. "I beat Mama," recalls Sharon. "I've been playing older women since I was 10 and wanted to win the title real bad, but I did feel funny afterward." To Mrs. Pritula the only drawback to winning is the trophies. "If these kids keep going," she complains, "I'll have to hire a maid to dust."