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.
Catherine I of Russia Catherine I (Russian: Екатери́на I Алексе́евна , "Yekaterina I Alekseyevna" , born Polish: "Marta Helena Skowrońska" , later known as Marta Samuilovna Skavronskaya; 15 April [O.S. 5 April] 1684 – 17 May [O.S. 6 May] 1727 ) was the second wife of Peter the Great and Empress of Russia from 1725 until her death.