And personally, I am not asking anyone else to play a sexless game, I would just prefer to opt out, with a setting, with a line of dialogue, I don't really care. It isn't the presence of these things which offends me, it simply doesn't interest me, though as a dude with a teenage daughter I have to admit I am a little bothered by the way relationships are handled in games.. There is a lot of fulfillment to be found in another person, sex is sort of the least of what relationships have to offer but I don't expect teenagers to get that and this isn't a dating sim anyway so these are all things I wouldn't normally bring up these forums.
I agree that romances should all be opt-in. Especially since there are sexual assault survivors who may struggle with characters being direct. Flirt dialogue options should trigger potential romance options. I think it would just lead to a better experience for everyone.
I wouldn't worry too much about your daughter. (I know, easier said than done.) For one thing, this is a mature rated game so the content isn't intended for children. But, even if she plays it or any of the other games with romance, the majority of people are able to distinguish reality from fantasy. I read the most absolute trash romance when I was a teen and I knew they were not accurate representations of reality. Also, games are not the most common media form where teens will get bad information on what romance is. Tv and movies are more widely accessible and have some of the worst examples of relationships I've seen. (I grew up on FRIENDS and... yikes.) An honest conversation can clear up a lot of confusion there.