Born in Coburg, Antoinette was the second daughter of Francis, Duke of Saxe-Coburg-Saalfeld, and Countess Augusta Reuss of Ebersdorf.

She was also the elder sister of King Leopold I of Belgium and the aunt of both Queen Victoria and her husband, Prince Albert.

Antoinette was regarded as influential,[1] and was bearer of the Grand Cross of the Imperial Russian Order of Saint Catherine.

She was buried in the Ducal crypt of Schloss Friedenstein in Gotha, where her husband and sons Paul and Frederick found their final resting place.

Her brother George wrote on 18 May 1802: "[...] The Württemberg couple didn't speak to each other in 2 years, but she was with child and certainly the father was some Herr von Höbel, a Canon.