In 1712, following the unplanned late pregnancy and ensuing resignation of the formidable incumbent, Henriette Christine of Braunschweig-Wolfenbüttel, Marie Elisabeth became Princess Abbess of Gandersheim Abbey, but she died the next year.

However, when the abbess, her sister, died in 1693 she missed out on the top job because her cousin, Anthony Ulrich, Duke of Brunswick-Wolfenbüttel, pushed through the installation of his own younger daughter, Henriette Christine.

The appointment to the regency met with opposition from Frederick William, Duke of Mecklenburg-Schwerin, and his nephew, who had been assuming that following the death of the Abbess Juliane Sibylle in 1701 the income from Rühn should come to the duchy.

The court delivered its "compromise", which effectively backed Marie Elisabeth, on 15 September 1705: she retained the regency appointment (and the income from Rühn Abbey that came with it) till 1712.

According to the art-historian Friedrich Schlie, the elaborate style of the tomb resembled that of the Abbess Christina's half-sister, Sophie Agnes (1625–1694), at Rühn Abbey.