I am admittedly rather far removed from the matter at hand, but I've seen how you've reacted to getting moderated over this and I can obviously see how much you've written here.
It comes across as very defensive, highly strung and, most of all, guilty. I have to agree with what TTakayaki said rather directly. Whole thing comes across as a case of "the writer's barely disguised fetish", only you're taking great pains to over-explain and defend it. This is further evident in other steps you undertook, or rather did not, such as failing to note the character's actual DOB where appropriate. So when you hammer the point about her just being young and that maybe being weird for the position it absolutely comes across as deflection, because most people aren't terribly interested in that.
Mentioned also your response to all this elsewhere, namely discord, in which you rather aggressively pinged all mod roles and some individuals also a couple of times, making accusations of bias, persecution and doing a quite frankly piss poor job of trying to paint them in a bad light. You aren't the victim of unfair treatment here, just of yourself. It is pretty inappropriate behaviour and a bad way to handle criticism. I worry that your response to people here will similar but I'll be happy if I'm wrong.
What I feel it all comes down to is a couple of options.
You can either accept what's being said, go with a character picture that's more appropriate and continue being transparent about the age going forward, or you can carry on, have a technically 'legal' if ill fitting image, skirt the line and continue to get weird looks/comments.
You're obviously desperate to dispel this stigma, so the former would be best. If people hold it against you after admitting to it, adjusting and moving on then quite frankly that's their problem. Otherwise, what you do in your own time is your own business and I'd be obliged if it remained that way. No one here needs a window into anyone's more dubious interests.
