Personally I think you should just say screw her. What can she do!? This is your creation as much as it is hers.
You did very nicely informing her about what you were doing, I don't see any obligation beyond that apart from the very very important of informing readers that you are using somebody elses work innyour own. That's all that matters. I can't see why at all anything else should or why it would matter what type of characters are being used. I sound frustrated, because I am :-). She's using somebody elses world I presume without asking or caring either.
Anyway thankyou for this story. It was brilliant to read, the ideas were great, and it was certainly interesting to not really know what was going on through the different perceptions as things were just assumed, but bit by bit revealed. I would love a sequel, and my choice would have it focused on Sam and Richard. I want to know where that goes. You've given hints, so I'll use my imagination, but I'm sure your story would be better. Anyway thanks again for what you have shared with us.