It sounds like how my sister and I are. She's biologically female but is every bit as transgender as i am but lives as a lesbian, and she looks like a guy. Like, she's gotten sired when she wears heavy clothes that hide the boobs. Her features are very...not sure how to describe. and her voice is extremely deep and masculine (way deeper than mine ever was). So she's like an androgyne.
Then me, I have feminine features. Even as a boy, I got ma'med a lot (never sir'd unless I had a crew, which was rare) and my voice never dropped during puberty. People who knew me said I looked like a 12 year old, they were always shocked at my age. I also have a very feminine shape and bone structure.
Also, we both knew since our earliest memories. Which is interesting. I'm not sure how common it is to have two transgender siblings.