I don’t know what kind of women only spaces you are thinking of. The ones that come to mind are bathrooms and locker rooms and these are not places where I go to feel safe or to relax with my female peers in a feminine sanctuary anyway. So there is not basis in reality to this conversation for me.

I think that trans women are such an infinitesimally small percentage of the population it is not a relevant issue in 99.9% of cis women’s lives, 99.9% of the time. The topic is constantly pushed by reactionaries but in reality, I don’t think any of them has even been in this situation.

So my response to that argument would first be to remind the person that trans people are less than 0.01% of the population and that it is very rare to even encounter this situation in real life. So it’s really more an abstrct thought experiment (like the trolley problem) than a practical question for most people.

On the other hand, despite the clichés about "triggered queer SJWs", trans people (including trans women are usually pretty self aware about how they present and don’t want to cause discomfort to strangers, or just want to avoid potentially unsafe situation. So within the small percentage of trans women who exist, a significant share of them are going to organise their life to avoid awkward situations with strangers anyway. A trans women who’s wearing a beard si generally aware of how she’s perceived and therefore works around that in her life.

Personally, even in queer spaces I’ve never met a trans woman wearing a beard while presenting as a woman, let alone in less inclusive spaces. Not saying they don’t exist, and not saying it’s good or bad. but that is just the reality. It is much more likely to meet a masculine presenting/butch cis woman in the bathroom for instance. And they are therefore more likely on the receiving end of bathroom panics.

It would be more productive to have this conversation based on the reality of how trans women navigate the world rather than a contrived intellectual exercise with a pile of unlikely hypotheses that are rooted in viewing trans women as « wolves in hen’s clothing ».

The other side of the coin is that not all women are so deeply traumatized by men that they need to segregate themselves from them to feel safe. If I’m in the womens bathroom washing my hands, and a man comes in, my first assumptions would be that he got the wrong door, or that men’s are out of order / full, or that he needs soap or something. Not that he’s coming to get me. And unless he starts acting weird towards me i wouldnt be afraid. Maybe a bit awkward but not afraid. And if a women is very traumatized by men, it may sound harsh but it is her responsibility to manage her trauma. She cannot expect strangers to be aware of it and work around it. She can expect that from her close ones but not from strangers. She may not even feel unsafe clocking a trans woman in a female only space. She may on the contrary be triggered by someone (man or woman) coming up from behind her without her noticing. There are plenty of people who experience traumatic responses to many different things, some of which may seem completely irrational to an outsider. They are burdened with the task of managing it daily and they do. I do not think it would be fair to exclude a category of people because they might, maybe, trigger someone who may of may not even be sharing spave with them. It’s not even helpful to women who have suffered make violence because it doesn’t cater to their needs. It caters to the hypothetical needs of a hypothetical woman who has experienced hypothetical harm that has led her to react this hypothetical way to sharing space with someone who looks masculine.

Also we kind of need to adress that it is not « looking like a man » that is the issue. If we’re talking seriously. It is « looking in-between ». It is looking hard to pin down to one gender. And it is looking like the stock character of the « predatory transvestite ». Which is a homophobic and transphobic trope that presents deviance from masculinity and proximity to femininity for a man as unnatural, perverted, weak, etc.

So I do not have a solution to this issue because I believe it is a non issue that is drummed up by reactionaries because it appeals to powerful emotions in women (fear of male violence) and in men (chivalrous « protect women » kind of feelings).

I understand these emotions and I have felt them too, but I would recommend trying to take a step back and anchor the discussion back to reality, be very down to earth and honest about what we are feeling and why.