I recommend looking in chapters 2 and 3 for the best textual evidence to support the initial argument provided. The reason to look in those chapters is because those two chapters contain a lot of narration about Cherry and her conversation with Ponyboy. I would specifically look in the section that immediately follows Ponyboy's flashback narration that explains what happened to Johnny to make him so skittish. Cherry is very empathetic about what she hears, but she is also strong enough and intelligent enough to defend the Socs. She tells Ponyboy that not all Socs are like the people that beat up Johnny, and then she tells Ponyboy that even Socs have troubles of their own.
"I'll tell you something, Ponyboy, and it may come as a surprise. We have troubles you've never even heard of. You want to know something?" She looked me straight in the eye. "Things are rough all over."
Cherry must be quite convincing with her words and non-verbal communication because Ponyboy tells her that he believes her. The chapter ends shortly after, and chapter 3 picks up events just after the movie ends. Ponyboy has been thinking about what Cherry said, but Ponyboy still knows there is something different between Greasers and Socs. He thinks that it is maybe the money. Cherry disagrees with Ponyboy and tries to explain that it is an emotional difference. She isn't quite as clear and concise as earlier, but Ponyboy figures it out. He realizes that Greasers and Socs both struggle with emotional health, but the struggle is on opposite ends of the spectrum.
"That's why we're separated," I said. "It's not money, it's feeling—you don't feel anything and we feel too violently."