SF's definition of a woman relies on gender stereotypes. Any reference to non-biological factors always comes down to social factors. There is no way whatsoever to define a woman as anything other than a biological female, without defining women based on stereotypes, it is impossible.
They try to obscure this by using language meant to muddy the issue, but there is nothing at all that can be said that alters the fact that they are reducing women to stereotypes. Their assertion of 'lady brain', i.e. the notion that the brain is gendered, again is reducing women to gender stereotypes as it's saying that most females have a brain that accounts for our social role & place in society, and some males have it too and should be treated the same as women even though society treats us entirely differently based on our different reproductive capacities
And there is no such thing as brain sex let alone brain gender. Scientists have been clear that there are not distinct enough differences between the brains of males and females for there to be a male and female brain, basically the overlap of any qualities generally male or female are too prevalent for their to be such a distinction.
And sex is not gender, so even if we had distinct brains, we know this doesn't constitute gender because we already know, as women, that we are not hardwired to be subordinate to men, and anyone who has taken the time to try to understand patriarchy understands that gender has always been a social system meant to uphold male supremacy; roles and norms have changed over time and place, but the only constant has been that their purpose is the subjugation of women, with the few exceptions only proving the rule: gender is socialisation, not innate, and we don't need a science degree to know this, we just need to know what we are as women and what is the tool of our oppression.