Margaret's brothers were Frederick II and Albert III Achilles, who successively ruled Brandenburg.
She married in 1423 Duke Albert V of Mecklenburg, but he died shortly after his marriage, even before they could begin living together.
[1] On 20 July 1441 Margaret married Louis VIII of Bavaria-Ingolstadt (1403–1445), to secure peace in the land.
[2] Through this marriage, Louis regained possessions he had lost to Elector Frederick I during the Bavarian War of 1420–1422.
In 1446, finally, Margaret secretly married her tutor, Count Martin of Waldenfels (d. 1471).