I think it's important to remember the full definition of woman as 'adult human female'.
I think the 'female' bit is often focused on especially as its the comparison to male.
However adult = not juvenile. Woman to girl/child is a bit like mare to filly/foal.
Female is the sex geared to produce large gametes. A woman is female in exactly the same way a cat can be female. But how are adult female cats different from women?
Human is key.
Lots of animals are 'adult and female' and they are characteristics shared across species.
Half the population are 'human and female' but some will be younger than 'adult'.
Woman only applies to adult human females.
We know humans are complex and intelligent with personalities.
By saying adult human males are women, you are saying adult human males are adult human females.
'Woman' isn't a gender, it's a descriptor of the age + sex + species.
That's why I think it's fundamentally incorrect to say there is such a thing as a female gender. Not all females across all species share a gender.
There is also no such thing as an 'adult human female' or 'woman' gender. There is not a gender shared by women. That's the conflation of sex and gender that is harmful and being exploited. It's like saying there is a female aura. It's that nebulous and disconnected from sex.
However there is a feminine gender that has been created by society. But feminine = / = female.
I feel it's important to remember the human part of adult human female. It's why GC feminists aren't 'reducing people down to their body parts' by highlighting the definition of woman. They are acknowledging both the sex and the humanity of women. That they are not just a sex, they are human with varying personalities, intellects and characters.
Woman doesn't refer to the human creation of gender but to the existence of human females themselves.