She was the daughter of George the Bearded, Duke of Saxony and his wife Barbara. Magdalena"s maternal grandparents were Kazimierz IV Jagiellon and his wife queen Elisabeth of Austria, daughter of Albert II of Germany. She was a granddaughter of the Elisabeth aforementioned,mother of the Jagiellonians, queen of Poland, who had claimed the Duchy of Luxembourg in 1460s as being the younger daughter of the last Luxembourg heiress Elisabeth of Luxembourg, Queen of Bohemia.
Joachim (1505–1571), the future elector of Brandenburg, was the eldest son and heir of their current claimant of Luxembourg, Joachim I, Elector of Brandenburg (1484–1535), the eldest son and heir of Margaret of Thuringia (1449–1501), Dowager Electress of Brandenburg, herself the eldest daughter and heiress of Anna, Duchess of Luxembourg and William of Saxony, Landgrave of Thuringia. Their son was John George, another future Elector of Brandenburg. After Magdalena"s death which occurred well before Joachim ascended the electorate, Joachim II Hector married Hedwig Jagiellon, daughter of King Sigismund I of Poland.
