Question: Who is the maternal grandmother of Princess Catherine Of Württemberg?
Answer: Henriette of Nassau-Weilburg

She was the mother of William II of Württemberg. Pauline of Württemberg (4 September 1800 – 10 March 1873) was a daughter of Duke Louis of Württemberg and Princess Henriette of Nassau-Weilburg. She married her first cousin King William I of Württemberg and was his consort