I understand she is frustrated. However, I think that because toilets are the thing that everyone uses so we can all relate to using them, yet it is the scenario that there is least support for single sex provision for, that is where the discussion goes.
Because very few people will disagree with refuges and prisons. A few more will disagree on changing rooms. But toilets will find women constantly saying ‘well my lovely trans friend is no threat’ or saying they don’t care. Hence the discussion.