I can find nothing about a person named Monna Delzant.
From kristine's photostream on flickr; doubled size and filled in shadows.
Miss Delzant wears a neo-Directoire dress with a cligy skirt and probable sheer over-skirt.
Keywords: 1913, Lucy Duff Gordon as designer, Lucy Duff Gordon, Lucile, Lucy Sutherland, Lady Duff Gordon, Monna Delzant, wavy coiffure, necklace, bodice, elbow length close sleeves, contrasting cuffs, waist band, maxi-length close skirt, shoes