What "important" thing is Prudence worried about ?

Prudence is very self-centered, which Sal notices about all the Winterbottom family. Instead of being concerned about her mother’s departure, or worried that she was kidnapped (as Phoebe believes), she is more concerned about whether or not she will make the cheerleading squad. This infuriates Phoebe, who feels that she is the only one who cares about her mother. Sal, however, had also noticed that Mrs. Winterbottom was practically ignored by the rest of her family, except when it came to “housewifely” chores like cooking and sewing. Sal sees how forlorn Mrs. Winterbottom is before she leaves. Prudence is only concerned about herself and whether she will be popular enough to be a cheerleader. Losing her mother has had very little effect on Prudence, much less that Phoebe or her father. Sal thinks this may be part of the reason that Mrs. Winterbottom left, and wonders if she had treated her own mother the same way before she left.