Her Wikipedia article is here. She apparently had facial hair problems.
From the Google Art Project via Wikimedia.
Princess Natalia wears a towering later 1770s coiffure adorned with feathers and pearl ropes, a lace scarf arranged like a fichu in the coming decade, and a watered silk(?) dress.
Keywords: 1777, Roslin, Natalia Petrovna Golitsyna, Princesse Moustache, Chernyshev family, Galitzine family, Princess, Lady-in-waiting, Catherine II, Russian, high straight coiffure, jewled feathered headdress, scarf, fichu, llave, vee neckline, bodice, square neckline, bows, close sleeves