Grandma’s genealogical sketch is here. There is no Wikipedia article for her, although there is one for her husband, Leopold, Hereditary Prince of Anhalt.
From Miss Mertens photostream on flickr; removed sepia tone, increased contrast, and enlarged by half.
Mom and grandma wear blouses and separate skirts. Grandma’s dress appears to have a natural waistline.
Keywords: 1909, Antoinette Anna von Anhalt, Princess Friedrich zu Schaumburg-Lippe, Elisabeth Alexandra Charlotte von Hessen-Kassel, Prinzessin von Anhalt-Dessau, Ascania family, Lippe family, Hesse family, Princess, German, bouffant coiffure, blouse, long full sleeves, long close sleeves, high enclosing neckline, elbow length full sleeves, cuffs, natural waistline, close skirt, necklace