The artist’s ambition was to present sitters as more than just mothers, referring to all elements that contribute towards a whole person capable of many achievements.
Did anyone look at the subject's anatomy (never mind the pregnancy line/linea nigra and other changes) and feel baffled as to the sex of the main subject? Did anyone think, 'just a mother'?
I wouldn't describe the sitter's image as androgynous so much rather than a 'woman wearing a moustache and embraced by young child'. However, I'm not someone who instinctively understands images | diagrams and I often have to look at them from a range of angles and distances.
https://www.npg.org.uk/assets/uploads/files/press/2024/Press-Release-TWPPP2024-Awards-2024.pdf
According to the press release above, we needed to understand that the moustache brings a third generation into the image. Let's guess the sex of the member of the 3rd generation that it was important to bring into a 'subverted image of motherhood'.