Well that is your opinion, I have mine. If you ask a question what is mature in my dictionary, what is not mature in yours? I mean, do I have to explain the meaning and feeling behind the basic words (I have not seen that it was required from other posters here explaining their opinions)? To me, her skating is more femminine and sophisticated than Mao's or, to lesser extent, Yuna's.
Joannie has a great presentation skill but I don't think femminine is a right word to describe her skaing. Just my opinion.