If your child is under 16, you need to be present for the consultation. You do not have to be on camera the whole time, but you do need to be there.
If your child is 16 or 17, they can consent to their own treatment. Some prefer to speak to me on their own, and that is fine. In practice a lot of teenagers want a few minutes to talk without a parent listening, and I will usually offer that even when you are in the room. If your teenager is being started on the Advanced Acne Programme, you will need to be present for that conversation regardless of age, so that we can go through the treatment and its requirements together.
Practical things: find a quiet room with decent light, no makeup on the day if possible, and have any current or previous treatments to hand so we know exactly what has been tried.