Honestly if you can her the book Principles of Economics and the Bitcoin Standard they both go hand in hand simply in the fact Austrian economics and Bitcoin Theory go hand in hand together, that it almost becomes unbelievably easy to see when you get to understand the two.

As for general concepts even though it may sound redundant, the bitcoin white paper is still her best bet to understand nodes and what a private key is, any futher explanation you can probably help her or refer her to certain videos