Really good question.  I don't know.  But I am pretty sure is she is not stupid enough to think that reality can be neatly categorized in legalistic fashion by mere words or formulas.  And if a white woman comes into her studio and tells her, "I'm black," I think she may be surprised, but open-minded and sophisticated enough to give that woman a sincere listen to see if her experience and outlook would fit the community's.  I am sure she considers each person on a case by case basis, and takes into consideration a range of factors.

Especially when it's a dance form with a tradition (however buried and denied) of male as well as female practitioners.

I'll have to ask her if the form of dance she has adapted did traditionally include male dancers.  If so, I would like to know what she would think of white choreographers/dance groups adapting those dance forms in such a manner as she did to exclude men.  If she did answer as I fear she might, then I would have to agree with your implication that her line of thinking is on the slippery slope to essentialism.

Truth unfolds in time through a communal process.