Um, part of the law and Hippocratic Oath is that unless the patient actively confesses to committing a crime, medical professionals are SUPPOSED to keep things said in therapy secret. That's basically the issue going on in the debate of pedophiles and "does merely saying you have an attraction to children in itself count as committing a crime when you're seeking therapy?"

As long as there's no smoking gun proof of the psychologist actively brainwashing the child into thinking they're trans, they're doing what they're supposed to.