1) The story sounds like preschooler fan fiction.
2) Even if it was real, the "alleged" bullying is nothing to worry about, it's not even bullying.
If she is a creepy obsessed fan (which she seems to be, still praising her even after being "bullied" - where is the self respect?) and Katy noticed that and didn't feel safe, she has the right to call her out on it.
Either way, I hope she's trolling for attention or on drugs or hacked or something because this is NOT going to end well for her.