You will not get a balanced or informed view on Mumsnet- it is well known as a hotbed of transphobia and the owners have made only very weak attempts to tackle it.
Here we go, throw out the transphobia trope, weak and unevidenced as it is hoping it will stick.
The vast majority of ordinary people do not care about trans people, it's not as if it's not entirely possible for a man identifying as a man to walk into a woman's toilets if they so choose anyway. Nearly all trans people just want to be left alone to be who they are without being harassed for it. You get predatory trans people no more often than you get predatory cis people.
The vast majority of ordinary people when asked do not support TW in women's spaces and services and the numbers rise every time the polls are done. By blurring the boundaries of who can use women's spaces the door is opened to all men. It's been shown that TW have the same crime pattern behaviour as any other men. Funny how we all have to validate trans people until one of them offends and then all of a sudden the trans community unvalidates them by denying their existence.
JKR is clearly traumatised by her experiences with men and seems to enjoy the attention she gets from punching down to an already marginalised and vulnerable group. It's a shame she's decided to destroy her own legacy, but she can have her opinion- I (and many other people) will just stop paying attention to her or buying anything related to her.
You think JKR enjoys receiving graphic death, rape and abuse threats? Let's be clear about this those people sending those threats are the ones who want to be in women's spaces and services. Her legacy is not destroyed it will be as a woman who stood for women's rights despite the most horrendous and chilling abuse and threats.
And yes, I have 2 daughters, I am not in the least bit concerned about them being in a cubicle next door to a trans woman.
Yeah, sure you'll make sure you perform the necessary validation and teach your daughters to do the same, very do it to Julia. Nice.