Maybe she's thinking of the 9th circle of hell - reserved for those who have committed "treachery," - and the fourth and deepest layer is for those who have betrayed their benefactors.
So, for example, if a woman benefits from changes in the law, brought in by the tireless campaigning of other women or if they get ahead in their field with the support of other women, but then refuse to acknowledge that let alone help other women in return, yep, that's pretty low.
I know I've name checked it many a time, but Andrea Dworkin's Right Wing Women at least gives some context for this phenomenon, as perhaps many expect that if one person was helped out, they'd be more inclined to help others in the future.
There's the old adage that as a woman you have to work twice as hard to get half the credit a man would. There's imho some truth in that - say if you are a woman in a male-dominated field of work where you could be treated by a freak, a pariah, certainly not "one of the boys," so even if you excel, those within the establishment around you will still not believe it to be true.
Then there's the old chestnut about if you can't beat 'em, join 'em, and you will find many women behaving and interacting in ways to avoid standing out as different, as a woman. One of those ways is to show solidarity with the culture and views of those who pull the strings. If the culture is anti-women, that means dissing women, individually and collectively. There is nowt to gain by showing any solidarity with women who haven't quite reached the place on the ladder you have. That risks reminding the influential men around you that actually, you aren't really one of them and you don't actually belong there. You could find yourself out on your ear after busting your ass to get where you are.
It's a kind of survival technique. No it's not noble, but there is a pretty good reason why some women not only aren't keen on helping other women, but sometimes appear to hold other women in contempt.