The narrator realizes that her father is not the invincible hero she thought he was.
Explanation:
The narrator , Lizabeth, is a girl who is growing up and this takes place in the context of the big depression in the U.S. Her father goes bankrupt and reacts desperately. Thus, when the narrator sees him cry , she realizes her father is weak. This is a sympton of growth since the girl can see that her father is a real man and not a hero any longer. Girls tend to idealise their parents during childhood, but this idealization collapses during teenage years.
Grandmother does not accept her son's guilt tactics. She knows when things are wrong and she voices her extreme disgust about the Nazi party to Bruno's father.