Phoebe is Holden Caulfield's little sister. She is ten years old, and Holden adores her. In fact, she is just about the only character that Holden Caulfield actually likes and respects throughout the entire story. Because she is his sister, and because he is the older brother, Holden feels the need to watch out for her well-being and protect her. Of course, it helps that Phoebe is patient, kind, and loving toward Holden. She's about the only character that Holden doesn't feel is a phony, and she is one of the few characters whose life matters to Holden. At the end of the novel, Holden is set and ready to run away. Phoebe wants to go with him, but upon realizing that his plans might bring harm to Phoebe, Holden agrees to stay home. Holden loves her, and he genuinely wants to do right by her.
In J.D. Salinger's The Catcher in the Rye, Phoebe is Holden's little sister whom he loves and adores. Holden describes her as cute, smart, and intelligent, but ultimately a true little girl. He values her opinion, but as a big brother, he also doesn't want to scare her or make her worried. He does his best to a good big brother, but since he seems to make a mess of his own life, he feels a little guilty that he's not as wonderful for his sister as he'd like to be. Phoebe even offers him some money when she finds out that he's in a spot of trouble. That's the kind of nice girls she is. This makes him really feel tender-hearted towards her and really loves who she is. He feels good when he's with her and she is his one true line to the family.