[citation needed] From her mother's first marriage, Margareta had two older half-brothers, Johann I (d. 16 November 1453) and George I of Schauenburg (d. young, 1404).

[1] From her father's side, she was a niece of Barbara of Celje, second and last wife of Sigismund, Holy Roman Emperor, King of Hungary and Bohemia.

In December 1444 Margareta married secondly with Władysław, Duke of both half Głogów and Ścinawa, member of the Cieszyn branch of the House of Piast.

Recognized her authority (although purely formal) over her dower, Margareta had to face the ambitions of Jan II the Mad, Duke of Żagań, who wanted to obtain the direct control over half Głogów and Ścinawa.

At the end, Casimir II renounced to all his claims over Władysław's inheritance in exchange of a monetary compensation from King Matthias Corvinus in 1479.