textbook:

Phoebe Caulfield is a strong part of her brother Holden’s life. She represents the innocent type that he so longs to protect from the world. She, in her youth and demeanor is the catch The Catcher in the Rye is trying to save… if that makes any sense. Phoebe is portrayed as a wise and mature kid. You can tell she’d be one of those completely cool characters and very little in life would rattle her. Opon growing older, i’m willing to bet she’d sort of steer clear of the fashion scene and would be a roll with the punches type.