The Monica Bird

There is no single variable we can point to that suggests someone is “really” female or not. Doing so for any individual trait will necessarily require excluding some cis women from the category. There are some traits that no trans woman possesses, but there will always be cis women who don’t possess those traits either. As such, there is no definitive way that you can suggest trans women are outside of the category “woman” but all cis women are in. At least not without going into tautologies like “only cis women are really women because trans women aren’t really women”. In so far as the term “woman” is to be at all meaningful and consistent, trans women must be included.