Talk:Princess Luna/@comment-24868254-20140519181914/@comment-4531340-20140520053845

That hasn't been confirmed in any official material; just because the black splotch on her flank didn't disappear along with the crescent moon doesn't necessarily mean she was born with it - for all we know, it could be a lingering artifact of Nightmare Moon (though that would bring up the question of why Rarity wasn't left with that - but if you really wanted to, I suppose you could explain that as Rarity had the Nightmare taking over her for a much shorter time period), or something along those lines.