Duchess Anna of Prussia [SEP] mother
Duchess Anna of Prussia
Duchess Anna of Prussia and Jülich-Cleves-Berg (3 July 1576 – 30 August 1625) was Electress consort of Brandenburg and Duchess consort of Prussia by marriage to John Sigismund, Elector of Brandenburg. She was the daughter of Albert Frederick, Duke of Prussia, and Marie Eleonore of Cleves. 
Biography.
Anna was married to John Sigismund on 30 October 1594. Before the marriage, his mother, Catherine of Brandenburg-Küstrin, pointed out that Anna was not beautiful, but the
Landgravine Amalie of Hesse-Homburg. Her mother Princess Frederica was the daughter of Prince Louis Charles of Prussia (brother of King Frederick William III of Prussia) by his wife Frederica of Mecklenburg-Strelitz.
Agnes was an older sister of Frederick I, Duke of Anhalt and Maria Anna, Princess Frederick Charles of Prussia. Through Maria Anna, Agnes was an aunt of Elisabeth Anna, Grand Duchess of Oldenburg and Louise Margaret, Duchess of Connaught and Strathearn.
Marriage.
On 28 April 1853, Agnes married Ernst