There are a number of Archduchesses named Magdalena in Austrian history. This one lived from 1532 to 1590.
Findagrave.com has this about her: "Austrian Royalty. Archduchess of Austria, daughter of the Roman-German King and later Holy Roman Emperor Ferdinand I, and Anna (Jagiello) of Bohemia and Hungary. She was foundress (together with her sisters Margarete and Helena) of the königlichen Damenstiftes in Hall, Tirol."
The Wikipedia article for Jakob Seisenegger is here.