You're not the first who's bringing this up. I'm not sure what Cari's stance is on this this, maybe he'll follow up on it later. I would say that the "adult" part of Eternum is deeply interwoven into the game and while someone surely could make adjustments to supress it, it would produce a shadow of the original experience.
It's a bit like the discussion of adding an easy mode to Dark Souls. There surely is some demand for it, but I doubt that the original creator will ever step up and do it himself. This one will prbly be up to the community to do if demand is high enough.
About your girlfriend, I have heard of a lot of people who had played Eternum with their girlfriends. It is targeted at men but also unusually popular with women, so maybe you can convince her to give it a shot, with an open mind. Maybe this video can help. Though be warned, girls usually like gay AVNs and you might be asked to reciprocate :)