Her maternal grandparents were Joseph I, Holy Roman Emperor, and Wilhelmina Amalia of Brunswick-Lüneburg. Her paternal grandparents were Maximilian II Emanuel, Elector of Bavaria, and Theresa Kunegunda Sobieska, the daughter of the King of Polish–Lithuanian Commonwealth, John III Sobieski. Josepha's mother, Archduchess Maria Amalia, was also a first cousin to her future mother-in-law, Empress Maria Theresa, and therefore Josepha was a second cousin to her future husband, Joseph, King of the Romans.
Her maternal great-grandparents were Joseph I, Holy Roman Emperor, and Wilhelmina Amalia of Brunswick-Lüneburg. Her paternal great-grandparents were Maximilian II Emanuel, Elector of Bavaria, and Theresa Kunegunda Sobieska, the daughter of the King of Polish–Lithuanian Commonwealth, John III Sobieski. Josepha's mother, Archduchess Maria Amalia, was also a first cousin to her future mother-in-law, Empress Maria Theresa, making Josepha a second cousin to her future husband, Joseph, King of the Romans.