Kitty's description is pretty Sue-ish- there's not enough time after her introduction to really establish her as a Sue, but the "trendy" descriptor combined with resilience is a warning sign. Still, there's not enough there to really pin anything on her.
But honestly, this isn't anywhere near bad enough to spork. It actually does seem to respect the Bartimeus canon, as far as I can tell. In fact, just judging from what I can see in the three chapters avaliable, I would probably read more of this. It's not super great, but it isn't bad either.
Ohmygosh, you have NO idea how good that makes me feel. This was the very first fanfic I ever wrote. And I binge-read the Bartimeus books beforehand to make sure I got the flavour right. ^^; I'm... more