GrannyMacawell
Once you accept that David's pronouns are her\she how are you going to ask her to leave the womans communal changing room? You have already accepted that she is a woman.
This is part of the problem. On their own, it might seem as though pronouns are trivial things that aren't worth getting hung up about, and as I've said, it seems to me that a lot of women have agreed for some time to use ones that don't sit well with them, in order to be accommodating, and to 'be kind', because of female socialisation.
But put pronouns into a bigger picture, and it's clear that actually they are not trivial at all. They are an acceptance that a man can 'become' a woman, and that women as we know them (us) don't exist. We've already seen on this thread that those who support the erasure of women don't even know what a woman is, and worse, they don't think it's important.
You are a woman if you 'just know' you are one, without knowing what it is that you know. If you can also insist on being called 'she', and accuse anyone who gets that wrong (perhaps on account of your beard, your deep voice and male-pattern baldness) of misgendering, and use your 'female' status to access places where women of the adult human female variety are alone and potentially vulnerable (hospital wards, prison wings and so on) you are going to be able, should you so wish, to subject women to significant trauma, particularly if you have a record of sexual assault.
Is it really any wonder that so many of the women who were initially willing to go along with this are now saying that enough's enough?
(and thank you, NanKate ?)