Gentle readers of all genders, I crave your indulgence. I’d like to quote a single sentence from someone who is now one of our least favourite fantasy authors, in order to illustrate a scientific fact about language.

Here’s the sentence:

“‘Harry, your eyesight really is awful,’ said Hermione, as she put on glasses”

—Harry Potter and the Deathly Hallows, chapter 4, “The Seven Potters,” by… well, you know who.

Two relevant points about this passage:

1. The pronoun “she” refers anaphorically to Hermione Granger.

2. At this juncture in the narrative, if you’ll forgive me for putting it so bluntly, Hermione has a penis and testicles.

(How do we know this? Well, Hermione has just drunk a potion that makes her physical form identical to that of Harry Potter. We know that Harry is amab, and that he subsequently fathers children who resemble him in ways that strongly suggest genetic inheritance.)

(We also know that the potion actually changes Hermione’s body, rather than creating an illusion in which she merely looks like Harry—note that the transformation affects her eyesight. Earlier in the series, the physical discomfort of such transformations is described in detail.)

(The existence of such potions has some rather dramatic ramifications involving privacy and interpersonal relationships, which have been explored in much greater depth in fanfic than they ever were in the series itself.)

Okay, back out of the parentheses. The two facts I mentioned upthread, taken together, illustrate very neatly, in a kind of Gedankenexperiment, that:

Pronouns reflect gender, not reproductive organs.

You probably knew that already, but the author seems not to understand it.

Hermione is still herself, and thus still a she, because her mind is still Hermione’s mind, even though her body has been temporarily made identical to Harry’s (and thus presumably has a penis and testicles).

(Holy Cartesian dualism, Batman! But hey, it’s fantasy.)

And this goes beyond pronouns. Hermione is still a girl,* even though she’s been “turned into” a (specific) boy, because her identity hasn’t changed, and being a girl is part of her identity, not a property of her physical form.

*Or a young woman; I think she’s 17 here.

You could hardly ask for a tidier demonstration of the fact that pronouns like “she” and nouns like “girl” or “woman” track gender (specifically, what @VerbingNouns calls conceptual gender; see https://www.glossa-journal.org/articles/10.5334/gjgl.721/#2-defining-gender), and that this is not the same thing as sex.

And yet the very author of the book in which this demonstration occurs, I am sorry to say, seems not to Get It.