Other than an Exile staton, Null might be in a Skaianet laboratory on Earth, or somehow already in the game in a lab in the Furthest Ring. Unless she's actually from one of those places in another session altogether. Possibly a survivor of a failed session trying to crash this one, which might explain how she knows so much. I'm still not 100% sure she's even human, though Jessprite would probably have mentioned Null being an alien.