1. Your novel isn't finished. You were kind enough to tell me in the first line saving me the time required to read the entire query. Finish the novel before you send the query.
2. The Heroin of your story wasn't drugs. Misused words, particularly when you're writing for kids are instant no.
3. Kid's books that, for lack of a better phrase, are vile. Really scary books and really mean books usually with a "should" theme: "this book will show kids should do this; parents should do that."
4. In your 250 word query letter there's nothing, literally NOTHING, about the novel other than the title.
These are queries that don't make it to the holding pen; they're rejected in about 15 seconds, the time it takes to skim a page.