In 1716, her father succeeded his brother Johann Wilhelm as the Elector of the Palatinate. By then it was evident that the Palatinate-Neuburg line (established by two grandsons of Duke George of Bavaria, Otto Henry and Philip) would become extinct, as Charles III Philip and his brothers had all failed to produce a legitimate male heir. It was also obvious that the related Palatinate-Sulzbach line would succeed them. Joseph Charles, the eldest son of the Count Palatine of Sulzbach, was the clear heir. On 2 May 1717, Elisabeth Auguste married Joseph Charles in a move that united the two lines. The sons of the union would be the indisputable heirs of the Electorate of the Palatinate, preventing another succession war. However, all their sons died in infancy and only three daughters survived.