This will be an unpopular thread in some quarters.
If a person is a legal adult, a parent can still advocate for their well being, but you can't expect others to believe your adult child was harmed if they don't believe that themselves. This is why adult detransitioners' writings and opinions carry more weight than parents.
Medical transition is not going away. That Pandora's Box is wide open & some ppl are going to choose it & persist. Some may even be happy with that choice. Of course a parent would prefer their child be happy in their own skin, w/out drugs, surgeries, irreversible changes.
Desistance is not a dirty word, though trans activists & some clinicians have succeeded in making it one, with their rhetoric that it's "transphobic" to believe it's preferable to desist than spend a lifetime as a medical patient, risking irreversible interventions one may regret
So it's not wrong or "transphobic" for a parent to wish for desistance. But some adults will go on to transition. Some--but not all--will detransition. Whatever they do, it helps no one to claim they are irreversibly ruined human beings, only worthy of being wept over or mourned.
Many detransitioners--& yes, some people who tell you they are happy in the medical choices they've made--are making important contributions to the growing, global conversation about the excesses & problems of trans activism & medical transition. They are anything but ruined.
The vast majority of detransitioners/desisters & ethical/concerned trans ppl don't want to be seen as wrecked poster children--especially in campaigns led by those who see LGB or even trans ppl as pitiful sinners who can and must be saved.
Every day, more detrans, desisted, & ethical trans ppl who see the problems w/youth medical transition are speaking up. Amplifying their voices is the best thing we can do. Even though we all KNOW adulthood isn't magically attained on someone's 18th birthday, the hard truth is..
...Those adults (some still very young) have to find their own way and their own voices. Those who detransitioned/desisted aren't being studied, & they are too often shouted down. How do we help them be heard? The future is in their hands.
No one knows what the persistence/desistence rate is going to be with the new, largely unstudied population of adolescent-onset (mostly) female transitioners is going to be. We need to push for research. And we need to keep trying to slow down the affirm-only train.
But if you want detransitioners/desisters on your side, mourning the loss of "beautiful" daughters who frequently didn't want to be seen as "beautiful" in the first place isn't the way. We can only help them be heard, not speak on their behalf--as hard as that might be.