In May 1600 in Wolgast Elisabeth Magdalena married Duke Friedrich of Courland. Their marriage did not result in any children. Elisabeth Magdalena was actively involved in politics and economic life. In order to support her husband’s political aspirations and restore her adopted son Jacob’s right to the throne, she corresponded with a number of national rulers, officials and their wives. Elisabeth Magdalena successfully managed more than twenty estates, where they cultivated rye, barley, oats, buckwheat and other crops and also sold them abroad. Elisabeth Magdalena took interest in gardening and medicinal plant cultivation, especially treatment of diseases and pharmacognosy. The Latvian State Historical Archives deposits her lists of plants for preparation of tinctures and remedies as well as the correspondence of the Duchess with pharmacists and doctors. Among them was Hermann Conring, one of the greatest German scientists of the time and advisor of the Swedish Queen Kristina, and also Johann Hövellius, physician and naturalist from Danzig who stayed in Riga in the 1630s.
After her husband’s death, Duchess Elisabeth Magdalena lived as a widow in Dobele Castle. Following her order Mežmuiža (Augstkalne) Church was built, and alterations were made or interior enriched in several other churches.
Duchess Elisabeth Magdalena was buried in the vault of the Dukes of Courland on June 29, 1649 in a pewter sarcophagus, which she had commissioned herself from Jelgava pewterer Franz Warnradt. It is decorated with three Pomerania-Wolgast coats of arms and three Brunswick-Wolfenbüttel coats of arms. On the lid of the sarcophagus there was once a crucifix. In 1884 the jewellery was removed from the burial to display it at the Courland Province Museum. A ring and a brooch with the initials of Duchess Elisabeth Magdalena can be seen at the Rundāle Palace Museum exhibition “From the Gothic Style to Art Nouveau”.