Amalie, Princess of Mecklenburg-Schwerin attributed to Georg David Matthieu (auctioned by Christie's)
This is all I can find out about her (from our-royal-titled-noble-and-commoner-ancestors.com/p4197), "Amalie von Mecklenburg F, b. 8 March 1732, d. 24 September 1775
Father - Christian Ludwig, Duke of Mecklenburg-Schwerin b. 15 May 1683, d. 30 May 1756
Mother - Gustava Karolina von Mecklenburg-Strelitz b. 12 Jul 1694, d. 13 Apr 1748
Amalie von Mecklenburg was born on 8 March 1732 at Grabow, Ludwigslust, Mecklenburg-Vorpommern, Germany. She (was) Canoness of Herford in 1746. She died on 24 September 1775 at age 43; Buried at Nicolai Church, Schwerin.
From Wikimedia; flaws in background suppressed with Photoshop by gogm.