A mother is not a father. There's a reason why "to father" refers to a single act whereas "to mother" is open ended. Women are the ones who risk health, even life, to bear a child. Women are almost always the one who takes at least months off work, with ill effects on their careers and financial independence. You can track populations and see the financial effect on women that motherhood makes over their working and childrearing years.
Becoming a mother revived my sleeping feminism. As a young, healthy, well educated woman in a female friendly profession I had felt very self-sufficient and free. Just one tiny baby was enough to crack that illusion.
It's difficult at work, Elusive, because in most places we avoid potentially controversial subjects. The very fact that your friend believed her position was uncontroversial is disturbing.
I think if it comes up again I'd ask her questions. What does she mean exactly? How does she define that? You know her and what would work best. But I would prepare something as it sounds like it is likely to happen again.