I have two children, both adults.
The elder is trans, he/him pronouns, changed name, planning to undergo a double mastectomy, and can tear up if JK Rowling is mentioned.
The younger is a gay not queer, lesbian who doesn’t do dick, who goes to radical feminist conferences and has her photograph taken with Maya Forstater and Helen Joyce.
I love them both dearly, but Christmas can be a bit fraught.
That's got to make family gatherings tense.
I've got two trans-identified niece/nephews. The elder is an autistic, gay male who fixated on the concept of trans as a late teen, and who decided to transition at age 23 after they were an adult. For the last four years, they've lived with another autistic, gay male who also identifies as transgender. Neither have undergone any surgery - nor do they intend to; neither takes any testosterone suppressants, both take estrogen. So far as I can tell... they're gay men who like boobs and wearing female-typical clothing. But my nephew-now-niece was a complete adult when they decided to transition. They didn't have any mental health issues, no depression or anxiety or anything else. They have had support from all of us in our family, even though I don't necessarily agree that he is a "woman". We talked about whether or not they might want kids at some point in the future, and uncertainty about that is a part of why they don't take testosterone suppressants - just in case. We also talked about how estrogen alone has effects that are almost entirely reversible in males, and that if at some point they decide to stop taking estrogen, they have a very high likelihood of losing the fatty deposits that give them a slightly more feminine shape, and can pretty much go back to living as a man without any real hiccups. There are simply some topics we don't talk about... and that's fine - we also don't talk about religion or politics.
The younger is a female and I'm about 99% sure that she was raped or traumatically assaulted over the summer while she was 16. Prior to that, she was a fairly typical teenage girl, not even a tomboy, and well-adjusted. She spent the summer with her best friend at her friend's grandparent's farm in eastern washington. She came back sullen, depressed, withdrawn, wearing baggy clothes, slouching, and having periodic panic attacks. After a few months, she announced she was trans, spent 30 minutes with a doctor at planned parenthood, and walked out with a binder and a prescription for testosterone. She recently had a double mastectomy. Her mother, me, and my mom had all tried to talk to her about what happened that summer, to talk through the ramifications of testosterone on a female body, about the fact that it's a one-way street that cannot be reversed, and that we want to make sure that her mental health is addressed first - her response was to completely cut off all contact with all of us.
Two entirely different underlying drivers for their self-declaration of transgenderness, two entirely different psychological profiles. The elder niecephew, by the way, does NOT think that their younger sibling is actually trans either.