Recently, this came up - influential film directors who happen to be female. A few came up, including Leni and Agnes Varda; Vera Chytilova from Czech new wave. Influential American....? P.S. In terms of acting, I am coming around to the fact that Sissy Spacek made American film in the 1970's not only generally better (in a muse-like way) but just plain gorgeous....can anyone else's face hold light the way hers seems to?
