Mischievous Baby

Sitting on the bus, looking at the hurried people outside the window and the shops, I remembered what happened to Zi Ning last night. "Senior, I'll go first, Beibei~~~" After saying that, he ran to the principal's office. "Oh, what a cute school girl!" Then she turned around and walked to the classroom. In these three sentences, the subject is missing... Also, it's best not to have the author YY in parentheses... Personal opinion, float away...