No such option? at the beginning of the confrontation when you reveal the evidence to her, there is a bargaining stage, I don't recall the exact options but I'm moderately confident something along the lines of what I said is an option. I think you establish she stole $1000 dollars worth of stock, and you demand it returned , her begs and counter offers 500, you tell her fine, show me some flesh, which moves onto 1-2 more layers nudity, then onto 2-3 more layers of sex with photos.
I can't comment on the walkthrough I've never used it, general rule of thumb for this game is never slack on the pressure.