flibbertigibbet \FLIB-ur-tee-jib-it\, noun:
A silly, flighty, or scatterbrained person, especially a pert young woman with such qualities.

We discover here not the flibbertigibbet Connolly describes but a serious reader (Goethe, Tolstoy, Proust) who found her cultural ideal in 18th-century France. -- Martin Stannard, "Enter Shrieking", New York Times, November 28, 1993 He argues persuasively that Millay's reputation has been harmed not only by academics who dread and fear her heartfelt "simplicity," but by the very admirers who wished to promote her as a kind of whimsical flibbertigibbet, a poetical Anne of Green Gables. -- Liz Rosenberg, "So Young, So Good, So Popular", New York Times, March 15, 1992