You do know that every trans adult was once a trans child, many before Mermaids even came along. In fact there wasn't even the world wide web for many as that only came along in 1989. Nobody convinced them they were trans. And why would anybody go through years of psychological evaluations and major surgery, with lifelóng dangerous hormones, just to be abused by people who received an unclassified biology GCSE and never reads actual modern science not written by Blanchard & Co.
Kids know the difference between being a tomboy and being trans - they know better than you do, even if they can't express it yet. And if you force them to be something they are not, that's child abuse. That's what the psychologists are for. And if you can't convince the medics, you don't get treatment on the NHS.
I'm afraid too many have been gaslighted by extreme right-wing evangelicals such as Keen-Minshull and Venice Allan and co. Sadly, many of you don't want to learn the science, just spout your phobic opinions.