I agree. the only thing that we can say scientifically is that someone has a specific amount of traits we have associated with the social label 'woman'. These traits are biologically speaking primarily related to reproduction and which role one would be able to fulfill the most effectively. Which does leave room for being able to fulfill both reproductive roles in some way or another.
Our social needs to mark ourselves and others as one of the two is deeply ingrained, but as it's such a grey area under the hood it would make sense to have a more fluid relationship with the topic.
Lunch is my favourite. Nothing beats a fine sandwich with cheese.