Often, as in the case of Keira Knightley, in her youth a girl may have the features of a softer (closer to Romantic) type, but as she gets older her body changes, forms and, finally, more dramatic, "Yang" features finally appear in her appearance.
That is why some women in 26-30 years suddenly face the fact that the style that suited them so well in their youth, now for some reason no longer adorns them.