I'm Chameleon

When the Doctor was going back, he passed by Scarlet's brother and patted his head as he assured him, "Don't worry boy, we will perform the surgery on you soon. You should come back to full health by the end of this week." Knowing the boy could be his potential family member in the future, the Doctor had to naturally be kinder to him.

Seeing the Doctor walk away, the confused boy quickly turned to his sister who was already walking up to him and tried to question her, "Sis… What did you—"

Unfortunately, she placed her finger on his lips to shush him and whispered, "Shh, we will talk after we are alone." She couldn't just admit out loud in front of everyone that she was just acting. 

After the talk with Anna and Katherine, she was much more convinced that taking part in that selection that Wuxing talked about was a good idea for her. Seeing the respect in which everyone treated the Seven Star members, she also wanted to be one.