Death
The imagery of death incites the novel because it is an experience which is completely foreign to Beka in her state of innocence. Death offers her knowledge about reality, fate, and even "God." The novel is largely about what that encounter with death does in her psychology. The major effect is that it makes her reckon her morality to the truth of death. In light of that reckoning, she realizes the knowledge that her parents already understood; they sacrifice so that she can live better because they know life probably won't offer as much time for them as it does for her.
Adolescence
The imagery of adolescence is concrete in the obvious ways—school, friends, gossip, and even unplanned pregnancy. But, in light of death, that adolescence is framed with grace as a kind of innocence. The frustration that she feels is a typical part of this imagery, as well as the enmity between parent and daughter. That conflict blooms into a sudden revelation, a personal realization that life is not promised to us. It was not an older person who died, but her friend, another teenager. Death is an imagery which inserts itself into adolescence with a dynamic effect.
Shame and religion
The imagery of church, religion, and shame is combined with educational imagery so that the process of indoctrination becomes clear. In Beka's defense, her life is filled to the brim with religious shame which makes her authority figures toxic to her psychology; if she automatically accepts their authority, their shame will have the unintentional effect of depressing her and lowering her self-esteem, so her anger and independence is in fact a defense mechanism. Religious shame puts her into emotional crises, and her character is defined by her responses.
Responsibility
Speaking of "responses," Beka's story is a journey toward responsibility. That means that she is able to answer for her decisions. The imagery contains the opposite imagery for contrast; her journey toward responsibility is defined by her refusal to accept responsibility for her decisions. Instead of owning her mistakes, she lies to her parents. When that lie is suspected, she doubles down and plans to betray her parents lest she should ever have to face them—she knows they will eventually find out; she is just afraid of their disapproval. It was because of their disapproval and her aversion to it that she chose to fail her classes, so this is an imagery of moral conundrum. Death is a crucible that turns that conundrum into the roots of her personal autonomy and responsibility.
