Premise: Princess Juliane Henriette Ulrike of Saxe-Coburg-Saalfeld (Coburg, 23 September 1781 – Elfenau, near Bern, Switzerland, 15 August 1860), also known as Grand Duchess Anna Feodorovna of Russia (Russian: Анна Фёдоровна ), was a German princess of the ducal house of Saxe-Coburg-Saalfeld (after 1826, the house of Saxe-Coburg-Gotha) who became the wife of Grand Duke Konstantin Pavlovich of Russia.
Hypothesis: Princess Juliane Henriette Ulrike never married