There is no double negative. In the antecedent of ... which will eventually take the double negative; we can only accept ... she knows nothing," with a double negative and arriving at an ...
Hate to say it, but... I have no set way of bubbling. I kind of go by whatever method seems natural at the moment. But I always do a quick little double check matching answer and question #.
Thank you to Corey and Dave for doing that and @nanchito I just posted a bunch of notes on a separate discussion for you to look at. Started out very conceptual and then moved towards actually working problems together interactively, it was great!