As a child, Elizabeth had a close relation with her brother, the future Christian II of Denmark. She was able to read and write in both Danish and German. On 10 April 1502 she married Joachim I Nestor, Elector of Brandenburg, in a double wedding alongside her uncle, the future Frederick I of Denmark, and her sister-in-law Anna of Brandenburg. Elizabeth and Joachim got along quite well during the first twenty years of their marriage and co-existed harmoniously. She received her mother in 1507, attended her brother Christian's wedding in 1515 and received Christian in 1523.

Her spouse was a pugnacious adherent of Roman Catholic orthodoxy during the Reformation. In 1523, she attended a sermon of Martin Luther's with her brother and her sister-in-law and became a convinced Protestant. In 1527, she received the Protestant communion in public: this meant a public break with the Catholic Church, and caused a conflict with her husband. In 1528, her husband asked a clerical council from the Catholic Church if he should divorce, execute or isolate her if she refused to renounce her new conviction. The church council replied that he should have her imprisoned.

Elizabeth escaped to the court of her uncle, John, Elector of Saxony, and a public debate broke out: the Protestant monarchs and her brother supported her, Luther supported her freedom to leave her husband for her religion, and she declared that she would return only if she was allowed to keep her conviction and if her husband renounced his adultery and his interest in astrology. Otherwise, she suggested that they separate, referring to the separation of her own parents in 1504. She was given a residence near Wittenberg. Her husband refused to give her an allowance and forbade her sons to visit her. In 1532, her uncle died and her brother was imprisoned, and she thereby lost her supporters.

In 1535, her husband died and her sons asked her to return to Brandenburg, but changed their minds when she made the demand that the parishes in her dowry lands be made Protestant. She finally returned in 1545 and stayed in Spandau.

The marriage of her son Joachim II Hector, Elector of Brandenburg, to Hedwig Jagiellon did not satisfy Elizabeth. Catholic services were held for Hedwig in her private chapel, and the Dowager Electress was also unhappy because Hedwig could not speak German.^[1]

Elizabeth's children were the following:

1. Joachim II Hector, Elector of Brandenburg
2. Anna (1507–1567), in 1524 married Albert VII, Duke of Mecklenburg-Güstrow,
3. Elisabeth (1510–1558), in 1525 married firstly Eric I of Brunswick-Kalenberg and in 1545 secondly Poppo XII, count of Henneberg,
4. Margaret (1511–1577), in 1530 married firstly George I, Duke of Pomerania and after his death in 1534 secondly John V, Prince of Anhalt-Zerbst,
5. John (1513–1571), Margrave of Brandenburg-Küstrin.

• http://www.kvinfo.dk/side/597/bio/795/origin/170/ (in Danish)