^ I personally don't think so, and if that's the case, that is the same for most celebrities (and even models) and even more so for everyone else. If you have good skin and good bone structure etc. that makes you naturally good looking, which I think she is. Also, she is as much known for her body as for her face. Obviously she doesn't look as polished and glamorous without makeup/hair done, but that's to be expected surely? And the contrast between dressed-down/glammed-up is much stronger in her case since she goes all out at events/red carpet.
.