That's exactly what was implied, yes. For me, I would prefer to play Fairest, because I have the most ideas for that Seeming, but I could also fit that into Darkling. Or Beasts, for that matter. 
Also it was brought to my attention that my initial idea didn't quite fit with the witch theme, mostly because I totally forgot. So ignore my last statement sorry. 
Adult themes are more than fine with me, no worries. 

(Also I apologise if the way I'm doing things isn't how they're normally done on a forum setting, I've never really played a game like this in such a thing. If I'm not following some sort of unspoken rule feel free to tell me, I'd much rather know than make a fool of myself.)