Figuring Out the ‘Nusach’ for a Women’s Zimun, Eh…

Wikipedia in its article on “Orthodox Jewish Feminism” provides an update on the female zimun for the Blessing After the Meal:
One formula for the women’s zimmun is exactly the same formula as the zimun of men, but substituting ‘chaverot’ (Hebrew: friends (f.)) for the word ‘rabotai’ (Hebrew: gentlemen) at the beginning of the invitation, thus feminizing the call.
Wait, shouldn’t it be ‘achayot’ (Hebrew: sisters), seeing as feminists are a big, warm “sisterhood”?!