The AAP has guidelines for the care of trans and gender-diverse kids. Here are two of their crucial definitions. Physical traits and social roles/expectations are lumped together. This sort of confusion is rampant yet forms the basis for serious medical interventions on kids.
People will sometimes deny that proponents of gender affirming care conceive of gender in terms of stereotypes. But it’s right there in the guidelines (and this kind of conceptual sloppiness is not unique to the AAP).
The guidelines categorize a kid who is distressed by some physical characteristics of her body--in particular sex characteristics--the same way they do a kid who is distressed by social expectations/roles. Diagnostically, this is a disaster.