How is the theme "coming of age" shown in the novel? Is there more than one example of this?

Lily begins the novel at age fourteen, a sad girl who has experienced far more than most have at her age. Leaving her abusive father, Lily must mature very quickly. With the Boatwright's Lilly begins to mature. She learns about life, love, race relations, and sex. Zach is the first black boy Lily has been attracted to, and eventually he kisses her.