Tsarskoe Tselo, now Pushkin, is located near St. Petersburg. Many palaces are located there and I do not know at which palace this portrait is located.
Natalia's coiffure dates this into the later 1770s. Her dress does not have a saque back so she wears a robe à l'Anglaise. Her bust is partially covered by a fichu.
Keywords: Ekaterina Nelidova, Smolny Pupil, Lady-in-waiting, Russian, high straight coiffure, floral hair ornament, vee neckline, elbow length close sleeves, forward-back flared engageantes, lace, floral bodice ornament, order bows, necklace, earrings