A bit aged for the role I think, but if she came back to her Tudors face, she will perfectly match an older Margaery ! It will be strange to see her as a candid and nice character, after the manipulative and darker Anne Boleyn ^^ Can't wait to see what she did with the character (after all, many characters look older than they are supposed to be ^^)
Yes, but Margaery's nice-ness is really a ruse for her character don't you think? It was funny how Cersei saw it, but for a while you think she's just being her usually bitchy self (which she was), but then you realize she's right! I always thought this actress had a real deviousness in her eyes and that makes me think she will work well in this role.
I think it's a ruse too, but beside that, she's (compared to other characters she has to face) rather "nice"... Witty, but nice ^^ She could make a good actress for her, but I will have to forget Boleyn which is more devious than Margaery, to me ^^ Then, they are two different roles, and she probably will make a good job with this one ! ^^