This is the weirdest conspiracy.
The only alternative is more than one conspiracy, which, well, isn't impossible but each extra conspiracy she posits makes the whole thing much less probable. She suspects her father is involved, but maybe he's just an asshole. She's certain a bunch of kids at school are involved, too, but she's not totally sure which of them are. The whole thing makes no sense, she doesn't even know what's a conspiracy for, but like they say, once is chance, twice is coincidence, three times is a pattern, and this is like the two hundred and twenty-first time.
She continues following the guy (seriously just what is that smell is he carrying a dead cat or something), trying to be as sneaky as possible.