Who is Julie LoPresti from All the Little Live Things and what is their importance?

Julie, Lucio and Fran's daughter, is described as a rebellious teenager, who sees to her parents as being oppressive and unfair. She is an avid rider of horse, and after Peck arrives on the scene, spends a lot of time at the neighbors. In the end, Julie is impregnated by either Peck or one of his friends. Her father has Jim arrested.