In the below video, you’ll see the over arching principles Mrs. Curwen uses to teach the staff. It encompasses facets from all five preliminary lessons. This is not something that would be taught in a single lesson.
If you follow the thread of knowledge she uses to teach the staff from Preliminary Lesson 1 through Preliminary Lesson 5, this is my interpretation of what you’d find.
One of the defining traits of her method to teach the staff is her use of the continuous intervals of the thirds.