Also, another fun fact;

All people have estrogen and testosterone. The rates just differ (and there’s variation too in what that affects more).

Puberty is triggered by a certain amount of fat reserves being present, due to estrogen and testosterone being made from cholesterol.

If estrogen dominates, fat is burnt slower, breasts develop and hips get wider, while hair is preserved and doesn’t grow thicker.

With testosterone dominance, more body hair develops (but for some, head hair may fall out later), the vocal cords descend, and the body generally burns fat more quickly in exchange for more (visible) muscle.

Some people have it inbetween, whether through HRT or naturally (eg. some intersex people). Same with body parts.