At that time, Yu Han said that she wanted to introduce Yuan Fei to Starlight Entertainment, but Yu Han did not recommend her personally. After all, it was overkill to trouble Big Uncle Chen Hai over such a small matter, so she handed this matter to He Meng.
He Meng knew that not only could Yuan Fei resist He Yu's temptation and not frame Yu Han, but she was also smart enough to trick He Yu. Hence, she had a good impression of her, so she recommended her to Liu Lu, who had a good relationship with her.
Although Liu Lu's status in Starlight Entertainment was not as high as He Meng's, she was quite famous in the industry and was very capable. Hence, although no one had told her about Yu Han's identity, she could more or less guess that Yu Han's identity was not simple from He Meng's focus on her.