She was the second daughter of Duke John III of Brabant and Mary of Évreux.

[2] On 13 April 1350 their daughter, Margaret III, Countess of Flanders, was baptized.

[3] Through this daughter, their only surviving child, Brabant came under the influence of Burgundy when she married Philip the Bold.

On 26 September 1371, Margaret and her mother-in-law, Margaret of France, countess of Artois, with their attendants, were guests of Philip the Bold, duke of Burgundy for supper in Lens.

[4] Soon afterwards, Margaret left Flanders and went to reside permanently, far from her husband, in the county of Réthel, where she died in April 1380 (after Easter).