Back when I was 8, I wanted to be just like my dad (before finding out his actual personality). I wanted to have the bodily characteristics of an AMAB person if that makes sense, IDK how to word it. I wanted to be mistaken for a boy, do the stereotypical boy things, reject makeup and dresses, and I went through a “girls stink” phase like some young boys did. I wanted my hair cut short because it made me look like a boy and even wanted to wear my dad’s clothes simply because they were “men’s clothes”.
“Girl" didn’t feel right to me but growing up in a certain kind of family, all I knew was the word “tomboy”, so I used that. But my family tried to convince me I was the most feminine girly girl, and that just wasn’t me. It felt wrong.
Use the words that you believe will form the desired image in the listener’s head. If the image you want to convey is closer to the listener’s concept of little boy than any other, use those words, regardless of what an uninvolved third party might think. It is better to speak the language of the listener to the best of your ability than to try to speak every language at once or just speak your native tongue louder, if that makes sense.