Her Wikipedia article is here.
From altesses.eu-princes190.php; size fixed at 27.2 cm high at 45 pixels/cm.
This shows a coiffure in the process of changing from the towering 1770s big curl styles to the bouffant 1780s styles.
Keywords: Friederike von Württemberg, Duchess Frederica of Württemberg, Friederike Elisabeth Amalie Auguste von Württemberg, Prinzessin von Holstein-Gottorp, Württemberg family, Holstein-Gottorp family, Duchess, Princess, German, high straight large curl coiffure, jeweled headdress, bodice, square neckline, draped jeweled floral bodice ornament, order sash, close sleeves