Misty's Twilight, Paperback/Marguerite Henry

Misty's Twilight is part thouroughbred, part Chinoteague pony, and one hundred percent fire and talent. A direct descendant of the most famous pony ever, Misty of Chinoteague, Twilight has greatness in her blood. Now it's her turn to shine, perhaps as a cutting horse, a jumper, or in the graceful art of dressage. Can Twilight, whose ancestors were wild ponies living on an untamed island, do it? Can she compute against the best horses in the world...and win?