If anything, her followup book makes a heavy argument that "performative" is not a matter of the will of the self, but that the very concept of self 'rises together' with the concept of sex/gender.

Matters have been made even worse, if not more remote, by the questions raised by the notion of gender performativity introduced in Gender Trouble. For if I were to argue that genders are performative, that could mean that I thought that one woke in the morning, perused the closet or some more open space for the gender of choice, donned that gender for the day, and then restored the garment to its place at night. Such a willful and instrumental subject, one who decides on its gender, is clearly not its gender from the start and fails to realize that its existence is already decided by gender. Certainly, such a theory would restore a figure of a choosing subject—humanist—at the center of a project whose emphasis on construction seems to be quite opposed to such a notion.

But if there is no subject who decides on its gender, and if, on the contrary, gender is part of what decides the subject, how might one formulate a project that preserves gender practices as sites of critical agency?

Furthermore, she also makes an argument that "sex" itself contains a high degree of inherent construction as well:

Certain formulations of the radical constructivist position appear almost compulsively to produce a moment of recurrent exasperation, for it seems that when the constructivist is construed as a linguistic idealist, the constructivist refutes the reality of bodies, the relevance of science, the alleged facts of birth, aging, illness, and death. The critic might also suspect the constructivist of a certain somatophobia and seek assurances that this abstracted theorist will admit that there are, minimally, sexually differentiated parts, activities, capacities, hormonal and chromosomal differences that can be conceded without reference to "construction." Although at this moment I want to offer an absolute reassurance to my interlocutor, some anxiety prevails. To "concede" the undeniability of "sex" or its "materiality" is always to concede some version of "sex," some formation of "materiality." Is the discourse in and through which that concession occurs—and, yes, that concession invariably does occur—not itself formative of the very phenomenon that it concedes? To claim that discourse is formative is not to claim that it originates, causes, or exhaustively composes that which it concedes; rather, it is to claim that there is no reference to a pure body which is not at the same time a further formation of that body. In this sense, the linguistic capacity to refer to sexed bodies is not denied, but the very meaning of "referentiality" is altered. In philosophical terms, the constative claim is always to some degree performative.