I wonder if Dumbledore briefed her on the trap.
My guess would be no. Generally speaking it's a good idea to let someone else in on a scheme like that, so that you have someone to scrape you out when things go horribly wrong; but wizarding culture seems a lot more secretive and heavy on information control than ours, which indeed may not be such a bad idea in context. You can't Legilemens something that someone doesn't know.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 118.
Plans for next chapter release:
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)