She was the mother of King Christian I of Denmark and ancestor of the Danish Royal houses of Oldenburg and Schleswig-Holstein-Sonderburg-Glücksburg.

[3][4] She was a daughter of Gerhard VI of Holstein-Rendsburg and his wife, Catherine Elisabeth of Brunswick-Lüneburg.

Through their father, they were cognatic descendants of King Eric V of Denmark (1249–1286) while through their mother, they were cognatic descendants of King Abel of Denmark (1218–1252).

[5] Through their father, they were also descendants of King Magnus III of Sweden.

On 18 April 1417 Hedvig was married to Prince Balthasar of Mecklenburg, who died of the plague in 1421.