She imitates him. Not only learn the sword, but also learn how to move your hands and feet. She was learning every posture of Su Yanran without knowing it.
The way he tilted his head slightly while drinking, the speed with which his jade-like knuckles moved inch by inch when he stroked the long sword, his light green and coarse yet elegant long clothes, even when he talked and walked.
Ordinary people, or Chu Qing in the past, probably think that these are called "etiquette" and are things that restrict people. But after spending time with him, he naturally felt ashamed of himself.
So she likes to learn these,
Just like it.