Situ Zha hadn't discovered his mother because the invisibility charm was still in effect.
It was Mianmian who suddenly remembered that Situ Zha's mother hadn't appeared. She quickly slapped invisibility charms on both herself and Situ Zha, only then could she see Situ Zha's mother, who had fainted on the ground.
Situ Zha, seeing his mother on the ground, was furious, "Su Mianmian, what did you do? Why did you bring my mom here?"
Feeling unjustly accused, Mianmian retorted, "Your mother came because she loves you. I asked her several times, and she insisted on coming to rescue you. What could I do?"
Situ Zha ran to his mother's side in several steps, but before he could help her up, he remembered how bizarre he looked at the moment.
So, he shrank again, transforming back into his original four-year-old appearance before reaching out to gently nudge his mother and, as in the past, called out, "Mom, mom, wake up. Don't sleep anymore, or the sun will shine on your bottom."