How does the author use foreshadowing in Eden Close: A Novel?

In Chapter two, Eden becomes a tomboy, forging a strong friendship with Andrew for several years that illustrates the theme of unrequited love. Their relationship is close, but Andrew sees it as a brother-sister relationship where Eden sees it as a boy-girl, love relationship. As Eden matures, she rejects everything she has been, including Andrew. This hurts Andrew in a way his childhood has not prepared him for. Eden is acting in a similar way as Edith, suggesting she knows no other way to deal with the changes that have come to her life. This behavior also foreshadows other changes in Eden's attitude in later chapters.