Maybe I'm picking up on the wrong thing, but the first thing I noticed was this: I braked hard, straight ahead on the pavement, released and turned onto the dirt.
Why? If I'm riding with my normal group of knuckleheads, then fine. But if we're on a road they don't know, approaching a decreasing radius turn or something, I'm going to warn them.
In the situation you describe, I would signal the turn early, slow early (assuming that she would do the same) and make it as easy as possible for someone with known confidence issues or low skills to be successful. Like I said, maybe I'm missing something obvious, but why approach at a speed that will require hard braking at all?