You are doing something that on a number of levels cannot be undone. In this case, depriving them of normal development alongside their peers. Most of these kids would have eventually outgrown these fixations and you cannot go back in time and undo the stunts in their development brought on even by puberty blockers.
Children believe all sorts of things about themselves that they will not believe in a few short years, particularly at middle school age and younger. I get to see this everyday. When adults take the role of enabler instead of loving parent/guardian who places reason and long-term health paramount in guiding decisions about children, they abdicate their roles not simply as parents, but as mature, moral human beings. We're supposed to be wiser than this. Your sample size of one notwithstanding, it's haunting to watch a child who is obviously mired in psychological disorder, so in need of a parent or other close adult who will simply step up and say, "You're struggling right now and we're going to get you help so you fixating on this anymore," rather than abdicating and instead saying, "Let's get you on some drugs or some surgery that will superficially make you appear as what you imagine you should have been."
Anyone who thinks it's right to perform sex reassignment surgery on a child is in sore need of a recalibration of his/her moral compass.