That's true, she is saying that - but that's not all she's saying.
If she were just arguing that things in the world can't be apprehended directly but only through constructed patterns of thought, the argument would be incontestable. But that's closer to the position of the "moderate critic" she's arguing against.
What she is really saying is that it is in some sense "not right" to talk about any extra-discursive "sex" because in doing so we presuppose that we can distinguish between an extra-discursive "sex" and a socially constructed "sex." Since her epistemological position is that we can't do this, she wants us to strictly abjure any attempt to talk about extra-discursive sex. My point was: Try doing that with the gas chambers and see how far you're willing to take your epistemology.
Seth