From pinterest.com/BelleBelvedere/r-o-y-a-l-s-t-y-l-e-i-n-b-l-u-e-1-9-t-h-c-e-n-t-u-/; fixed all edges and removed spots with Photoshop.
This portrait shows Empire (1804 and later) style with the lace cherusque and probable constructed bodice.
Keywords: Elizabeth Alexeievna, Luise Marie Auguste, Prinzessin von Baden, Princess, Tsaritsa, Baden family, Romanov family, German, long curly coiffure, bandeau, necklace, earrings, square neckline, lace neckline ruff, lace bertha, brooch, jeweled bodice ornament, upper puffed sleeves, arm bands, waist band, Empire waistline