"National Velvet" is the warm-hearted story of a little girl and her love for a beautiful thoroughbred horse. Based on Enid Bagnold's best-selling novel and the MGM film, the TV version has been moved in locale from England to an American dairy farm region. It remains, however, the simple heartwarming story of Velvet Brown, a 12- year-old girl, her horse, and her great dream of winning a famous steeplechase.