A post card with this image post marked 1913 was recently posted to eBay.
Posted to the Alexander Palace Time Machine Discussion Forum by Grand Duchess Ally on 5 March 2009.
Maria Adelheid's sleeves appear to have three tight gauzy layers emerging from the upper sleeves and she wears a tight skirt in this photo.
Keywords: Maria Adelheid, Princess, Grand Duchess, Nassau-Weilburg family, Luxembourgois, bouffant coiffure, scoop neckline, bertha, ruffles, lace, bows, elbow length tight sleeves, blouson bodice, tight skirt, floral bodice ornament, order sash, necklace