again, what if due to some tragic event, she became delusional and image her lost child as this stuff pony, and she believe it has a mind of it own, but it clearly saying what she want it to ,say if she was a real child, and the trouble she believe she would of have to deal with,
the teach clearly didn't give the no pets in class rule, which lead me to think it was just a plushy and he's face expression shows that he didn't know how to deal with it, the fact that she looked back at every one after talking to it mean that people was watching her most likely because they believe she was crazy, therefore i truly think this story is about a insane woman
i think this idea of the story would make a great alternative ending
The teacher refered to it as a Ro-pet, meaning, he believes it to be a robotic pet, probably built by her father, the scientist. So he just let's her keep it, and if she was delusional, than so would all three of her friends, her father, and the bully, who Celestia teleported.