From eBay.
Catherine is riding in shorts, rather than side saddle, and she shown in uniform in this print.
Keywords: Prisekin, Catherine II, Princess, Tsaritsa, Ascania family, Romanov family, Russian, long curly coiffure, feathered hat, jacket, high neckline, long close over-sleeves, cuffs, buttons, pockets, long under-sleeves, pants, hosiery, shoes, uniform, equestrian dress