How is that relevant for the parent asking advice about their teenage daughter So maybe they are closer together in terms of life stages, than implied in the post. They provide counselling, advice, or referrals to helpful services. In 3 years they will be a perfectly acceptable couple. And many of these are not age-related. I would concentrate on exactly this, and only this.
You ol' dog, you!
16 year old dating a 24 year old?
It's happened before and it will happen again. The main thing is to set some standards. I suggest trying that. Things are above-board and within bounds, it seems. And what can she miss? That's not to say that you shouldn't already disapprove - while I personally wouldn't start feeling disapproval just from what you've described, your feelings are very understandable - but regardless of how you might initially feel, you can always tell her you disapprove a little later, once you've gotten as much of her perspective as she's willing to share.