In a fine picture-book debut, Gibson neatly weaves insights about a child's development into the stock plot of a beloved pet turning up with young after a mysterious disappearance. Little Quack has been Jackie's best friend; the other farm animals are too busy to play. Still, the duck (like Jackie) needs her own kind, too. A warm story about friendship, growing, and self- reliance; in her perceptive, impressionistic illustrations, Denton observes the lonely child and his animal friends with amused affection. (Picture book. 4-8)