is it possible to be modern and fertile? So far, the answer appears to be ‘no’.

She is also wrong as she is using 'modern' as if it is absolute term instead of relative. Taking 'modern' to mean "characteristic of the present age", then every generation is 'modern' compared to past generations, and so yes, there were in fact modern and fertile societies.

What she really means is:

is it possible to be feminist and fertile. So far, the answer appears to be ‘no’.

But stating it that way would be too hard-hitting for her and her feminist audience.