She is fun to write. I have about three of her in my head now. Canon, of course, now that we have actual details; WeakBetrayed!Narcissa, who Lucius only married for familial connections and an heir; and Strong!Narcissa, who doesn't take guff from anyone. :D The first HP story I actually finished was a Narcissa story, in fact. And before that, I never would have even thought about writing her.