Who is Ling from Death of a Red Heroine and what is their importance?

Ling is Chen's college girlfriend. The child of an important Communist Party official, their romance ended when she took an opportunity to visit China and the couple realized the political inconvenience of their match. Chen has never gotten over Ling, and the feeling is mutual. They remain in contact. When good events happen, Chen writes to Ling. At his lowest point, he turns to her. It is not really because of her influence, however, but because Ling is the person that Chen truly wants to share his life with in all its highs and lows. Though Wang is the overt romantic figure of the first half of the book, Ling is the true romantic figure. She remains in the background until the final chapter when she appears, reuniting with Chen and bringing the promise of a happy ending.