How does Deja challenge her father's authority in the novel, Towers Falling?

When Deja's elementary school wants to teach students about 9/11, but Pop does not think Deja is old enough to learn about it. In this case, the school challenges his authority. He tries to pull the "As long as you live under my roof" example, but Deja shoots it down quickly, challenging his reasoning. They do not live under his roof. They live in a shelter.