Frances Anne Spencer-Churchill, née Vane, Duchess of Marlborough (Sir Winston Churchill's grandmother)
A print of her at a committee meeting in 1885 is found here. Her daughter in law Jennie Jerome is the subject of this Subalbum. Her Wikipedia article is here.
From eBay; the image had numerous spots amd most of them were removed with Photoshop. Spot removal resulted in loss of detail in the upper part of the image.
This photo shows the twilight of the crinoline as Frances Anne Vane, now a Spencer-Churchill, wears a coiffure with bun and long sausage curls and a half cone crinoline with a round waist band instead of a vee waistline.
Keywords: F. R. Window, Francis Anne Vane Spencer-Churchill, Vane family, Churchill family, Duchess, British, long straight coiffure, headdress, bun, off shoulder vee neckline, bertha, lace, waist band, natural high waistline, crinoline, over-skirt, necklace, earrings, brooch, bracelets, fan