She married on 11 September 1597 at Wilhelmsburg Castle in Schmalkalden with Count Ernst of Schaumburg (1569–1622).

Hedwig constructed a Princely Mausoleum in the St.-Martini Church in Stadthagen.

She gave her nephew William V an annual pension and later bequeathed her bond and all her dower rights to the county of Schaumburg to his widow, Landgravine Amalie Elisabeth, whom she also appointed executrix of her last will and testament.

Hedwig died in 1644 and was buried in the Princely Mausoleum in the St.-Martini Church in Stadthagen, next to her husband.

An epitaph above her grave reads: There is no other, holier decision of widowhood, than to pass down to the living that which was entrusted by the last will and to guard it, when it is realized.