Su Jiaxin is Su Ningxin's younger biological sister, a legitimate daughter of the Third Branch. She is about twelve or thirteen years old, cheerful, and close to Su Ningxin. During the coming-of-age ceremony, she clumsily combs Su Ningxin's hair, causing pain, and Su Ningxin inwardly complains. She greets Su Ningxin happily and represents the genuine affection among the younger generation. She is not involved in schemes and seems innocent and straightforward.
