Art and expression
Without a doubt, the most important aspect of the siblings' character development is their passionate creation of art. The novel is one long depiction of the art and expression that their selves portray. They want their mothers approval, and then the academic approval of apprenticeship and admittance to important institutions, but at the end of the day, it is their point of view that makes them artistic, and their journey toward being artists is a journey toward caring less about what others will think about their art.
Sexuality and taboo
The novel depicts the blossoming sexuality of the two siblings, the straight sister and the gay son. They both experience attraction to guys, but the sister is perfectly allowed while the brother feels immense pressure from his awareness of taboo. He knows he is different than the majority, and he senses that other people's judgment will be part of his journey toward sexual fulfillment. Notice that the sister is losing her virginity when her mother dies, another portrait of sexual taboo and the loss of innocence. Yet, in the end, this sexual journey leads both siblings to partners. The shame was a brokenness in their point of view that was solved when they stopped feeling sorry for their desire to be happy in life.
Death and sorrow
The novel has one point of view before Dianna's tragic car accident, and a radically different one after the crash kills her. Before, there is competition for Dianna's love and attention. Apparently, Dianna's marriage also featured that competitive element, because she has an affair with someone she likes more than her own family. The kids struggle with those emotions until one day, Dianna is killed, and then their emotions find a new rock bottom. Instead of anger and confusion, they now see the world in the colors of death, sorrow, and despair. They sorrow at the facts of the matter and despair because they don't know how to stop feeling guilty for the accident, as if they had anything to do with it.
Hope and the future
The novel depicts the characters emotions as consequential, depending on their relationship to time and the future. Their hope comes in the end of the story when they find out that their lives have not disqualified them from attaining a good future. The death of their mother and their strife hangs over their head, but there is a stark difference in their point of view before and after they find their spouses. The spouses are imagery too; as minor characters, they represent what each person desires, which is a path forward and life and a companion to share their burdens with. They attain that goal by pushing through seasons of hopelessness.
