I mean, without getting into complicated discussions about gender ideology and intersex people and all that stuff, I think it's safe to assume if a AFAB person who presents as Female but who gets herself a cock via magical, supernatural, or parascientific means, either by her own will, by accident, or because of it is forced on her, all specifically so she can tie it to sexual intercourse and reproduction, then it all depends if whatever stuff grew her cock to begin with also happened to alter more of her internal phisyology.
This to say, is her cock now "connected" to her kidneys, or is it a vestigial limb not connected to the rest of the body, some sort of parasitic body attached to them? It should be a case by case thing, especially since most classic Futanari designs have the cock usually grow, with no balls, from the woman's clitoris, thus separated from her biological urethra.
Either way in the case of Ophelia it's the later, the cock literally only grew because she cannibalized and made grow her unborn son inside of her due to the pill, thus developing the "parassite" cock, so I'm 90% sure she would pee from her pussy.