As a reminder, be sure to properly give content warnings and put sensitive subjects behind proper spoiler tags. It's for the mental health of not just your comrades, but yourself as well.
Here is a screenshot of where to find the spoiler button.
what is the innate womanness that cis women have which allows them to just WAKE UP THAT WAY that rans women do not?
There is no such thing as "innate womanness," but obviously very few cis women put effort into appearing female. That is simply how their bodies and mannerisms will be viewed by others by in their default state. It's correct to say that most cis women have to put effort into appearances, but the vast majority of those that don't will still be seen as female 99% of the time. You're trying to convince her that there's an equivalency between this and what she experiences when there's not. Cis women don't put effort into "being girls," which is what her comment was about.
She said that her sisters still effortlessly pass as women after waking up, which is obviously correct, and someone said this was "a couple steps away from doing phrenology," which is absolutely absurd. It's not a fair comparison at all, and she was at least more correct to recognize this than to think that she's seen the same way as her sisters