"What is the humane, workable answer for women like these?"
Simple, they're not women, and should not be allowed in the women's bathroom. Why do biological females, who have fought hard for female only spaces, have to conform to a mentally ill man's whims? As such, they can go in the men's bathroom, because they are men. They can find a unisex bathroom. Women, real biological women, should not have to suffer because of mentally ill men.
Also, your son, not 'daughter', is mentally ill and saying such is not dehumanization, its facts based on medical science. Him taking hormones, acting feminine, growing out his hair, etc... does not , and will not ever, make him a woman.
The mere fact that TRAs such as yourself suggest that men, who dress feminine, are somehow women, shows you are misogynistic and do not grasp that dressing feminine does not make you a woman. To further add, there are masculine women who have short hair, wear men's clothes, and have mannerisms that are masculine, but they are STILL WOMEN.
Work on that internalized misogyny, and get your son help.
Look at these women.
Laverne Cox. Ella Morgan.
Both are transgender women. Both live and present publicly as women.
Now imagine telling either of them that, because of the sex they were born, they should walk into the men’s toilets.
What happens next?
How safe would they feel? How would the men around them react? How many questions, confrontations or humiliations might follow?
This isn’t theoretical to me.
My daughter is a trans woman. Like many trans women, you wouldn’t know she was trans unless she chose to tell you.
And the current situation has consequences for her everyday life.
She worries so much about being challenged when using public facilities that she sometimes avoids drinking when she is out so that she won’t need to use a toilet.
Read that again.
A young woman deliberately restricts how much she drinks because she is frightened about what might happen if she needs the loo.
As her mother, I find that completely unacceptable.
Whatever your position on the Supreme Court judgment, surely we should be capable of acknowledging the human consequences of how it is interpreted and implemented.
Women’s safety and privacy matter. I am a woman. Of course they matter to me.
But trans people’s safety, privacy and dignity matter too.
These things do not have to be mutually exclusive.
So I keep coming back to a very simple question:
What is the humane, workable answer for women like these?
Because saying “use the men’s” may sound remarkably simple from behind a keyboard.
Living it is something else entirely.