how would you specify which woman you mean in a same sex couple? i am personally not in need of this term but think its an especially good fit in this specific

how would you specify which woman you mean in a same sex couple? i am personally not in need of this term but think its an especially good fit in this specific context. context being the defining factor, i would usually not appreciate explicitly reducing a person to their reproductive organs like this but in a discussion about reproduction it actually removes ideology from my point of view.