Well, what I've seen in most text books is a grammar structure. There's usually a unit for adjetives, another one for verbs, past verbs, negative and past adjetives, and so on. Also, the kanji learning sometimes goes through a completly different textbook.
What she does is teach all the grammar, writting style, kanji and conversation you would need to survive in a specific situation. For example, in the 'stations' situation we learnt how to ask for tickets and directions, the mentioned kanji and how to write all of this down. Some situations make more sense with the speaking part, others with the writting.
And no, she doesn't follow a textbook, but I guess she mixes a bunch of them.