For me, it's not even a matter of this champ's body type (which, quite frankly, is fine to me) but a matter of logic. In fact, I think Sejuani looks awesome! =D However, she lives in frigid temperatures, yet wears little clothing? I just wish there was a bit of continuity there. Going off of what IronStylus has been saying, I think I would still be able to tell that she was female if she had some fur covering her up a bit. (I mean fur is fashionable! ;D ) And even if you couldn't, I don't think it would matter much. I mean, Kayle looks fantastic, as does Shyvana. I'm not an artist, but I don't think that showing more skin is necessarily the answer here.
Either way, I still think she looks good. Albeit, very chilly. =P