Here it is. Only the person who experiences the task (in Goldilocks' case, eating and sitting) knows whether or not the task is too hard, too easy or just right. As an Empowered Music Teacher, you may make suggestions as to what you think is possible for your student, but in order for a student to become accountable for their own progress (and responsible for the there lack of) they must also become responsible for creating their own goals. Goal setting, or what I prefer to call goal GETTING, (anyone can set a goal, getting or achieving that goal is an entirely different matter) is an acquirable skill.
One of the most important things an Empowered Music Teacher can do to create accountability in their students is to remove themselves from the student's playing field. A coach doesn't get on the field with his players. He stays on the sidelines and lets the players play their game. Yes, he provides feedback and suggestions, he may even call a play, but the players must execute. The same goes for the student-Empowered Teacher relationship.
The students need to look at themselves in order to become accountable for their progress. They cannot look at their teacher and say "You chose the challenge and it was too hard. You made me do it." If this was the case (as it was for me at the beginning of my career), the hard truth is, the student is correct. If the student was not part of their weekly curriculum making process, they can then take the focus off of themselves and place blame on the teacher. That's why it is imperative that the teacher observe, make the student aware and potentially suggest solutions, but, it is up to the student to either accept the solution or come up with a different set of goals and then decide how much or how little they will achieve by the next lesson.
the student should set his or her weekly goals.
Here's what you can say to your student, "Is this so hard/much, that you will feel frustrated and not successful by the next lesson? Is it too easy/small that you will not create a feeling of accomplishment for yourself and instead feel bored? Or is it just right that you will create a feeling of pride and achievement by having to apply yourself? You choose."