Actually, "gender" is primarily a grammatical term, as in the feminine or masculine gender of a noun or pronoun. "Sex" is the correct term to differentiate males and females. No need to amend anything. Gender has been hi-jacked as a "softer" word for sex, since "sex" now also refers to "the act".
As I said, the same reg that allows family members otherwise ineligible for dependant status (like parents and siblings) entry in B2, allows the non-working person in the same-sex couple the same privilege, like it or not.