Julian is talking about a very small subset of women who call themselves radical feminists and the article is all about how they really shouldn't be calling themselves radical feminists, given the attitude towards mothers.
She's not saying this is typical of radical feminism. She's saying this is a small group of hyper-privileged people appropriating radical feminism. It's an interesting article and I agree with her that it's yet another example of how identifarians appropriate and corrupt language to misrepresent themselves and their beliefs.
At the outset of austerity, I noticed similar dismissive attitudes towards mothers from people I'd call "media feminists". Those of use who were trying to point out the intersections of austerity cuts - welfare, women's services, legal aid - that would compound so that working class women would have their equality curtailed were told such things as not all women are breeders on the regular.