I noticed a thread on the hell hole of twitter yesterday, by a man, talking about the lack of women in gaming, then called us "non-men". He also used the word "man", no trouble at all with that! He genuinely couldn't see the issue with how offensive that was then called all the women objecting terfs and had a blocking spree.
THAT is offensive. When you don't use the word woman to describe the female sex class but instead call us people with a cervix, bleeders, vagina havers - THAT is reducing us to our genitals, THAT is offensive. Woman is not.
Having to consistently alter your language at a moments notice to someone else's ever changing personality gives that someone a sense of power that should not be wielded; the power to be the most centered and the most important person in the room. The power to demand constant validation and affirmation through compelling others language, and the underlying threat of fallout and attack should you not comply.
Growing up is a hormonal minefield as it is. If you're outside the norm, not very popular etc, this idea that you can change how you identify and that makes you cool and interesting, and gives you that power I mentioned above. That is going to be very very appealing. I was that teenager, awkward, with feminine and masculine interests. I was desperate to be liked. If I thought non binary would do it, I'd be on it like a shot.
But we're all non binary. It wouldn't mean I was different and therefore special. I needed to find my place in the world, not demand the world adjusted itself to me.
Anyway, (after that essay!) DD is 4 so I'm hoping this issue will be in the long grass by the time she hits her teens. But I would be limiting and keeping a strict eye on social media, having chats about the reality of sex, peer pressure, and about how she does not have to limit herself because her sex is female; there is no right way to be female, and having stereotypically masculine interests does not mean she has to call herself a boy. I would encourage her to push the boundaries of what it is to be a girl/woman, not regress into a box labelled boy/man. And that of course, you cannot change your sex.