If you take her to a pretty good movie, she knows it's a pretty good movie.” Through this we come to see the kind of closeness they share, that they go for movies together and that her brother loves her company because she has a very humorous personality. If you take her to a lousy movie, for instance, she knows it's a lousy movie. I mean you can even take her anywhere with you. I mean if you tell old Phoebe something, she knows exactly what the hell you're talking about. In chapter 9 we learn of Phoebe being Holden’s “kid sister.” However it is only in chapter 10 that he paints and image of her to us. He sees her as hi confidant, the one who he can go to with any problem and who he can have a conversation with. It is through this that we see the strength of their relationship and how reliant he is on Phoebe. We all see him wishing to call her again when he goes into the Lavender room at the Edmond Hotel. We see this when Holden jumps off the train at Penn Station and Phoebe is one of the several people he thinks of calling. Phoebe is seen as Holden’s support structure a she is the one who he confides in and goes to.

In “The Catcher to the Rye,” Phoebe is seen as a flat character while her brother Holden is seen as a round character.

A Flat character is one who does not go through significant changes throughout the novel and who also serves as a support system to the min character.

Flat vs. round characters