Her mother Amalia was a daughter of Infante Francisco de Paula of Spain , a younger brother of Ferdinand VII of Spain .
Isabella 's father Adalbert was the fourth son of Ludwig I of Bavaria and Therese of Saxe - Hildburghausen .
Isabella 's mother Amalia was a daughter of Infante Francisco de Paula of Spain , a younger brother of Ferdinand VII of Spain .
Isabella 's father Adalbert was the fourth son of Ludwig I of Bavaria and Therese of Saxe - Hildburghausen .