According to her Wikipedia article, "Frederika Louisa of Hesse-Darmstadt (Friederike Luise; 16 October 1751 – 25 February 1805) was Queen consort of Prussia as the second wife of King Frederick William II.
Frederika Louisa was the daughter of Louis IX, Landgrave of Hesse-Darmstadt, and Caroline of Zweibrücken. She was born in Prenzlau. She was the sister of Grand Duchess Louise of Saxe-Weimar-Eisenach, as well as Grand Duke Louis I of Hesse…”
