I don’t work with children, however, when I have worked with young adults, I do agree that meeting with them alone is essential, though I do like how you were able to observe the interaction with the parent in the beginning. I feel like young adults often have more stress from personality traits driving symptoms and from social media making them feel afraid, uncertain, lacking confidence and threatened – especially for girls. Bullying can be more of a factor with children also, and they may have experienced sexual assault or experiences that frightened them, pregnancy, etc. or even, been perpetrators and now, racked with guilt. You would be less likely to get to the bottom of it with a parent there.