In what year did Sigismund Casimir's mother die?
Cecilia Renata of Austria Archduchess Cecilia Renata of Austria (German: "Cäcilia Renata"; Polish: "Cecylia Renata"; 16 July 1611 – 24 March 1644) was Queen of Poland as consort to the Polish-Lithuanian Commonwealth's King Władysław IV Vasa.
Katarzyna Kostka Katarzyna Kostka (1576–1648) was a Polish–Lithuanian noble lady.