Who was the mother of XXX?
Princess Friederike Luise of Prussia
Princess Friederike Luise of Prussia (German: Friederike Luise von Preußen) (29 August 1714 -- 4 February 1784) was a daughter of Frederick William I of Prussia and Sophia Dorothea of Hanover and Margravine of Brandenburg-Ansbach.
Sophia Dorothea of Hanover