Shen Lian smiled, "Let's not learn then. However, I need you to do something for me, and you must not refuse." With Shen Lian's level of cultivation, he saw through Fang Yanying since the beginning. He only did this to test her heart of Dao.
Chen Jianmei only managed to attain something having immersed himself in the Shapeless Sword Incantation for ten over years. Fang Yanying did not have the luxury to be distracted by something else.
Even when faced against Shen Lian's authoritative presence, she was able to refuse his offer. This showed that she had guts. Despite his gentle appearance, after he had attained immortality, Shen Lian was at a Celestial state. His words and actions were more authoritative than that of a human Emperor, and it was difficult for anyone to say no to him.
Despite her gentle physical appearance, Fang Yanying was strong-willed. No wonder Chen Jianmei took a liking to her and took her in as his direct disciple.