There are striking parallels between Phoebe's and Sal's experiences; particularly as they concern each child's relationship with her mother. Sal's mother apparently went through a crisis of identity after her second child was born dead and she was rendered unable to have any more children, and Phoebe's mother faces overwhelming turmoil when her illegitimate son comes back into her life. Both mothers feel that they must have some time alone to overcome their difficulties; the only problem is, Sal's mother is killed in a bus accident, and never returns, leaving Sal with unresolved feelings of abandonment and guilt. Throughout most of the story, Sal is unable to come to terms with what happened to her mother, and she refuses to think or talk about it, because to do so is too painful. When Phoebe's mother disappears, Sal is forced to deal with what happened to her own mother because of the parallels involved. By watching events unfold in Phoebe's life after her mother's disappearance, Sal is able both to empathise with her friend's grief, and to better understand her own mother's dilemma in leaving the family she loved. By sharing Phoebe's ordeal, Sal is better accept what has happened in her own situation.
Idioms are language or dialect which are peculiar to a certain people, cultural, or geographic group. The use of idioms gives the reader a sense of what the characters in a story are really like. For example, Gram and Gramps use several colorfully distinctive terms in their speech, such as "the whole ding-dong country," and "huzza, huzzah," and they call Salamanca "chickabiddy," which is a familiar address for a dear child. The use of these words enable the reader to get to know Gram and Gramps similarly to how Salamanca herself experiences them, and much more intimately than if they were simply described in the third person.