I think that video demos on youtube do the teaching job pretty well and are the best resource for painters. Here there are only a couple of examples with any steps at all. Definitely not for beginners, But it has many examples of work, and each lists her primary triad that she used to begin/set the mood in color. So I can see myself flipping through as a reference if say, I don't know where to begin painting a desert southwest scene or a snow scene or a mountain with snow so that I can use that triad to begin.
There is not even any clear advice on a beginner palette for landscape. So overall feels like many landscape paintings from this artist thrown together in the book, with a one line note on triad of colors that is the base for the painting. That said, her paintings are simple yet have punch, and you can learn a lot from studying each and trying to copy the effect if you admire her work. If you follow her guideline, you get the interest from not using premixed colors