Therese was a daughter of Frederick, Duke of Saxe-Altenburg, and Duchess Charlotte Georgine of Mecklenburg-Strelitz, eldest daughter of Charles II, Grand Duke of Mecklenburg-Strelitz.
Therese was a child of Frederick, Duke of Saxe-Altenburg, and Duchess Charlotte Georgine of Mecklenburg-Strelitz, eldest offspring of Charles II, Grand Duke of Mecklenburg-Strelitz.