Li Weiwei didn't believe Hao Jian's claim that nothing was wrong. If it really were nothing, Gu Peng, one of the school's top bullies, wouldn't be causing trouble for Hao Jian. From their interaction, it was clear that there must be some unknown grudge between Hao Jian and Gu Peng.
As a teacher, and especially a homeroom teacher, one can tell if a student is lying just by their demeanor. If a student wants to lie to a teacher, their eyes will wander, not daring to meet her gaze. And indeed, when Hao Jian spoke earlier, he made just such a small gesture.
She immediately realized that Hao Jian was lying. However, she also knew that if Hao Jian didn't want to speak, she couldn't force him to talk. So she decided not to press further, though her eyes remained fixed on Hao Jian, filled with doubt.
