classically balanced profile aligned to our western culture’s standard definition of an attractive female
Way to admit that it's not about the person's wellbeing but about conformance to some kind of peer pressure, maximized with a claim that it represents society and its ideals as a whole. Aside from the fact that you are apparently describing your own ideal, which is not without implications (other comments explained).
at 23, her determination to get a double mastectomy
Meaning self-affirmation as an adult.
I should have given her the mission of protecting her sacred body
"Sacred" meaning your wish to enforce their denial of their identity disregarding them, to impose yourself unto someone else.
so-called professionals and medical providers, might want to tamper with her body
False conspiracy theory, libel. This pushes the lie that somehow, your son was pressured into becoming a man. The reality is that they self-affirmed to be, including resorting to available professional help.
Some would obsess about it, and others would try to convince her to alter its essential integrity
Exactly what you claim that you should have imposed on him. That's projection. If you care about them, you could try to understand, to support them and their choice, instead of blaming them, dehumanizing medicine, blaming society and yourself. If you're in a community who persecutes him, or persecutes you because of that, you may consider leaving that slum...
One may even perceive the glorification of child abuse with the intent to imprison them and prevent them to grow and develop autonomy, while grooming them into submission with religious rhetoric like "sacred".