What are the motifs in The Face on the Milk Carton by Caroline B. Cooney?

Family and personal relationships are a motif in the novel. At the beginning of the story, Janie's relationship with her parents is established as loving and functional. Their closeness is increasingly strained with each new discovery that Janie makes about her past. In contrast, the Shields family is strained at the beginning but Reeve becomes increasingly accepted by his parents. Although he has struggled with his siblings, it is ultimately with the help of his sister, Lizzie, that the Johnsons and the Shields come together to help Janie contact the Spring family.