If Holden were to write a letter to Jane, what would he most likely talk about?

Probably how he hates the world except her. She is the only non-phony thing in the world besides his sister Phoebe.

he would talk about the time they had spent together after having met. He would also talk about how often he attempted to get into contact with her but didn't get to he would want to know what happened between herself and Stradlater