You seem to have taken what she said too literally, and going from over control to lack of control because you thought somebody told you to won't be a good defence.
Because of some of the harsh comments you have made to others here, without any other attempts to help except occasionally recommending religion, I was surprised to hear you were so far into your training, and my thought was, perhaps it's private and fee paying? Or a faith based specific training. Because some trainings where you pay fees to them, especially private trainings, often keep you longer, for obvious reasons I guess. Or give you more leeway before taking action.
I did not say this to you, because you were so harsh and dismissive to my comments prior in that conversations that I didn't want to interact with you further.
I am a well qualified therapist and trainer of therapists. But whatever type of training it is, at the stage you're at, they would expect you to ask for more guidance if you felt that you had been asked to do something that was leading to uncontrolled sessions. The skill in working with children and young people is partly about how to engage them without being controlling, balanced with thinking about safety and progress.
You have maybe taken too much of a black and white interpretation of what was said. Recall that I mentioned to you a friend in therapy training who described a way he sometimes noticed himself acting as, Inflatable Jesus?
You didn't say whether you understood that comment of mine, which was helpfully intended, but told me all the things you thought about me and my posts none of which were complimentary.
However that friend had massive potential and was in many ways excellent at his work. He was good at self analysis and self awareness, which is an important central skill. But I think he was talking about that same dilemma of how to effectively manage a session without either being an Inflatable Jesus in his words, and taking control, or letting go of session management, which risks wasting the clients time and money.
I think you could rescue this by thinking about and reading up on this issue of managing sessions fruitfully and effectively, which is indeed challenging and more so with children and young people, especially if a parent or guardian is not also present, though that poses other challenges. I don't know your modality, but there's some great stuff out there to read on this.
And rather than complaining, I suggest recovering the situation with your supervisor. How is your relationship with her normally? What can you build on? I would review how you have previously communicated with her too, and take advice about how you come over from a colleague or colleagues you trust.
Pre qualification, it's very unlikely that your point about what you see as conflicting advice will be helpful, because you will be asked why you didn't raise that when you saw the results in the room of your interpretation of what she meant. It's your therapy session to manage, not hers, she supervises you on the basis of what you tell her and has now raised the problem. You would also likely be directed to reading that explores this issue in depth, which is probably already on your reading suggestions.
I hope this is helpful, and I wish you well in fulfilling your potential in this work, and in a training in which you have to develop a lot of self critique, and sometimes a get a certain amount of ego knocks. Read up on that area too, there's great stuff on this for you, with clear guidance.