I don't think there is a one size fits all answer.

What do we know? Well they all have SOs and they wear women's clothes.

I would be willing to bet that when you get down to it, each one is different. Also I bet that few if any can answer the why question, other than because it feels good.

Don't you normally do things you like and avoid things you don't.

Your not trying to say that men and women think the same?

Women are closer to their feelings generally speaking.

The women I rent a room from told me she was hesitant on renting a room to a transgender person because they are so emotional .

Yes I am, it's the way I have always been.

Really the only question you should want answered is do they want to transition or live full time as a woman. They may not know, and/or the answer could change with time.

I know that this is something that you likely did not sign up for. I admire you for having the courage to work through this.