As far as I can tell, she is a postmodernist who started out as a Marxist, but has later abandoned it. At the very least, it doesn't seem to have had any prominence in her works, which are focused on personal psychology and feminist theory.

I do admit that I may be completely off base, I know very little of her beyond what I could find on Wikipedia (which does list her as Marxist, but provides no further insight on why) and a handful of scholarly articles.

Note: a much better example you could have given was Slavoj Žižek, to which I have no answer..