How was the stealing of the second book a pivotal point in what was to come?

Liesel is shocked by the realization that Hitler is responsible for the death and disappearance of her family, yet Hans forces her to publicly salute the Fuhrer, fearing what would happen if others heard her say she hated Hitler. Unable to admit her true feelings, Liesel boldly commits her first act of defiance against the Nazis by stealing a banned book in public. Here, Liesel's motivation for reading and stealing books evolves from sadness over her brother's death to rebellion and vengeance against Hitler. Liesel's mode of retribution is, however, not violent. Her very first action upon making her realization is to help and make peace with Ludwig, the classmate she savagely attacked earlier. Her immediate response to the hatred espoused by the Nazi speaker is one of friendship.