Could it be that it was only right for Nan Nan to sacrifice for Zijin, regardless if she was good or bad?
"Forget it. There are some things that can't be said clearly to you. It's alright as long as Mom and I understand." Qiao Zijin refused to communicate with Qiao Dongliang. She had long realized that in this family, only she and her mom had a common language and could understand each other's words and inner thoughts.
Her dad was biased. Even if what she said was reasonable, when it reached her dad, her reasoning would only become distorted. Since she knew that this was going to be the result, why should she waste her saliva and efforts to argue with her dad? There wasn't anything to gain from it.