The tomb of Marie d'Agoult (1805–76), who also wrote under the pseudonym Daniel Stern (as recognised here). Agoult is noted for her (sometimes stormy) relationship with George Sand, and for her depiction as Béatrix in Balzac's Béatrix (1839).
Goethe appears prominently in the background here: Agoult is noted for her writing on Dante and Goethe.
Link to my earlier post on Père-Lachaise:
Le Cimetière du Père-Lachaise / Père Lachaise Cemetery