I think that would be way too complicated. Plus, the whole point of "the fixer" in the game is to be underestimated when you are actually capable, even when looking like a school girl or like a teenage whore (the whole haven quest is just about that). I don't see where a maturity stat can help you.
I think the actual atractiveness stat is more than enough. Although, down the road, having clothes with unique effects and dialogue would be an interesting thing.