Old Crone I would talk to them whatever age they were in age appropriate language. I have always answered my kids questions about sex, death, sexuality and any other issues, however difficult, as openly and honestly as I can, and said where I might be wrong. I would discuss any issues which affected them. My daughter has a debilitating condition which has resulted in blindness, hearing loss and low life expectancy. She is also bisexual. You can believe I have had difficult conversations.
How would I select what to cover? I'd give them my view, the gender critical view and any other sources of information I consider reputable. I'd have them talk to other people I know and trust. I would respect their views in an age-appropriate fashion.
I am against puberty blockers for many reasons, and taking the step to effectively sterilize someone is not one to be taken lightly. Watch and wait is the right approach. This would require at the very least a diagnosis of gender dysphoria, and not just self-id. The fact that Mermaids encourages all transgender children and their parents to give puberty blockers when only a proportion of transgender people are dysphoric is deeply troubling.
WarpedGalaxy
What’s wrong with just telling your son, you are a boy but that doesn’t mean you can’t wear dresses, nail polish and play with dolls DadJoke? All boys and all girls can dress in whatever they like and play with any toys they like?
Yes, of course I'd say that. I even said I'd say that. I'd also tell them that just because they are attracted to someone of the same sex, doesn't mean they are a different gender.