Criticisms to Simone de beauvoir's theory that women are the 'second sex'? Watch
1 - Her line of argument depends heavily upon language, in particular the French one. It is not impossible to concieve of a language where the male was "othered" and thus her criticism is highly contingent. Indeed, if we were to adopt the old Anglo-Saxon norm of prefixing both he male and female versions of "man" as opposed to only prefixing the female variations then the linguistic critique would fall flat.
2 - Her argument is very abstract, there are no concrete political goals and thus it is difficult to talk about a De Beauvoirian activism (which should surely be the point of all feminist literature?)
3 - She assumes that gender is entirely socially constructed, and has no real answer to developments in things like genetics or biological understanding which give rise to arguments of a "biologically essential essence". (The general feminist riposte to these arguments is to attack the sequence of causality, but De Beavoir herself has little to say on the subject)
4 - Her engagement with psychology was largely based on Freud, and we have moved on significantly since then.
5 - She adopts the values of a patriarchal society and asks how women can be better emancipated within them rather than calling for a withdrawal from that mode of living or, better yet, it's overthrow. Many people see this sort of feminism as the root of the "have it all" woman who now has to work twice as hard since she is expected to have a career and do the "womens work"; it may not be emancipatory at all.
Hope that's helpful.