Sabrina's response to "Powder"

In Tobias Wolff's "Powder," the roles of the father and son seem to be switched. The son seems to be more responsible, mature and tight (for lack of a better word) while the father is basically the opposite: less concerned and kind of a loosey-goosey kind of guy. I am going to use this same sort of character development within the short story I am working on. Two of my characters will have charactersitics that are not stereotypical of their role. Certain characters are expected to take on a certain role. My characters will either somewhat switch roles, or just not completely take the role they are expected to.