How old are they? Primary, tweens, teenagers, adults?
What level are they? Young beginner, older beginner, intermediate or advanced, transfer students
What are their strengths and weaknesses? Pulse, rhythm, pitch awareness, reading, musical phrasing, theory, key signatures, scales, aural exam preparation?
What is your goal? Why Kodály? You’ll have more success and add more value if you have a clear goal in mind.
How much time have you got? How long are lessons and what else do you need to cover in that time? Is there an upcoming performance or exam, or are they changing teacher soon?