Posted to Foro Dinastias by Katyusha on 10 September 2010; distributor's marks on the right were cropped.
The complex sleeves, blouson bodice, and shallow vee waistline are 1900s so this photo from date to about the time they married in 1906. Wikimedia posts another version of this image and lists it as having been taken in Cannes in 1906.
Keywords: 1906, Maria Immaculata (1874-1947), Maria Immaculata Borbone, Principessa di Borbone delle Due Sicilie, Princess Johann Georg, Borbone family, Wettin family, Princess, German, straight coiffure, high enclosing neckline, collar, lace, elbow length over-sleeves, engageantes, long tapered under-sleeves, blouson bodice, shallow vee waistline, A-line skirt, pin, gloves