Don't let her intimidate you with the fact that she has read the game. If that book was all you know about game then you're in trouble champ!
You already did a mistake by trying to act like you didn't read the book, just so you know it's a pretty generic book by now. Not that big of a secret anymore. You should have teased her about it and made very good and sexual conversation material out of it.
This happened to me once before, I found out that one of my girl friends is reading the game, I noticed her putting it in her bag. So I made it a challenge for myself to close this chick. And I did.
Go direct! Fuck memorizing lines and routines that probably a million goon around the world is now trying and failing with.