So Francis who has son prince Ferninand, who was father of Ferninand II had also son named https://en.wikipedia.org/wiki/Ernest_I,_Duke_of_Saxe-Coburg_and_Gotha and he "married on 31 July 1817 to Princess Louise of Saxe-Gotha-Altenburg (1800–1831); father of Prince Albert, the husband of Queen Victoria."
Francis of course had a daughter also https://en.wikipedia.org/wiki/Princess_Victoria_of_Saxe-Coburg-Saalfeld who then "married on 21 December 1803 Carl Friedrich Wilhelm Emich, Prince of Leiningen, had issue. After his death, she married on 11 July 1818 Prince Edward Augustus, Duke of Kent and Strathearn, the fourth son of King George III of Great Britain, the mother of Queen Victoria."