As someone who has first-hand experience with a family member transitioning, I've mainly learned that you don't have to agree with or even understand a person to love them. Love is unconditional.
Regarding your post subject, I've also learned that strictly speaking, sex and gender are considered two different things, so asking about the "sex thing" is really not typically appreciated by those most directly concerned.
Having said that, I know this is the off-topic section of the forum but one of the things I most appreciate about this forum is that it can be a place where people of all backgrounds and beliefs come to discuss and share experiences about living a frugal nomadic life. Not politics, or religion, or gender. The interwebs are positively overflowing with such discussions. And some of us encounter it in daily living, whether we choose to or not.
Personally, I could care less if someone self-identifies as transgender, non-binary, gender fluid, cisgender or one of the other gazillion gender labels (Facebook, for example, offers users 56 gender categories to select), anymore than I care about labels of other kinds, but I get more than enough of that stuff from daily life and countless other websites. There are precious few places to find first-hand information about frugal nomadic living!
Now you kids get the hell off my lawn, dammit!!
Peace.