This is why it would be valuable to hear from people who identify as transgender or nonbinary, about their experiences from this particular stage of their lives -- to find out what, if anything, they specifically would have viewed as supportive when it came to their upbringing.

You're absolutely right that parenting involves a lot of tough decisions and uncertainty...and some better context would help take out the guesswork from the perspectives of parents whose children confide in them that they are "different" from other kids.