Hi, and welcome.
Just my personal experience here, but I'd completely toss out the "conduct disorder" diagnosis. It works as a label when they can't find another label that fits at the time. Provides validation that the parent is not insane... the kid really has a problem. But there are no treatments nor medications that help with conduct disorder, as far I can tell (research and experience).
Probable developing paranoid schizophrenia is a tough enough diagnosis to begin with. And it, alone, probably accounts for all of the behaviors. They are likely using "probable" and "developing" because she is so young, and they really don't want to nail down this serious of a diagnosis so young - she's only 11.
I'm not a specialist on schizophrenia. Others here have some experience with it and may have some advice.
