JENNA'S BIG JUMP

As an only child and the new kid in fourth grade, Jenna suffers from loneliness made only worse by the taunting of class bully Buzz; but her misery is mercifully curtailed when Kate Bradner joins the class and becomes a friend. Kate—who wastes no time putting Buzz in his place (though she also has some sympathy for him)—is the oldest of four children whose family has moved to a Minnesota farm. The Bradners' barn is the site of Jenna's ``big jump,'' her leap to the kind of bravery she admires in her mother (one of 11 adventuresome siblings) and in Kate—the kind that comes from being a little impulsive and from making one's own decisions. Jenna's swing from the hayloft results in a broken arm, but even this turns out to be only a temporary setback in her quest. Thureen's Jenna is hardly a match for Ramona Quimby, who's invoked on page two—she doesn't have Ramona's vibrant personality, nor are her experiences nearly as entertaining, while her story has the first novel's common flaw of overexplaining. Still, a workmanlike effort that younger or less sophisticated readers may enjoy. (Fiction. 7-10)