thumb|Nathalie de Lage de Volude Burr served as a guardian to Nathalie de Lage de Volude (1782–1841) from 1794 to 1801, during Theodosia's childhood. The young daughter of a French marquis, Nathalie had been taken to New York for safety during the French Revolution by her governess, Caroline de Senat. Burr opened his home to them, allowing Madame Senat to tutor private students there along with his daughter, and Nathalie became a companion and close friend to Theodosia. While traveling to France for an extended visit in 1801, Nathalie met Thomas Sumter Jr., a diplomat and the son of General Thomas Sumter. They married in Paris in March 1802, before returning to his home in South Carolina. From 1810 to 1821 they lived in Rio de Janeiro, where Sumter served as the American ambassador to Portugal during the transfer of the Portuguese Court to Brazil. One of their children, Thomas De Lage Sumter, was a Congressman from South Carolina.
thumb|Nathalie de Lage de Volude Burr served as a guardian to Nathalie de Lage de Volude (1782–1841) from 1794 to 1801 during Theodosia's childhood. The young daughter of a French marquis, Nathalie had been taken to New York for safety during the French Revolution by her governess, Caroline de Senat Burr opened his home to them, allowing Madame Senat to tutor private students there along with his daughter, and Nathalie became a companion and close friend to Theodosia. While traveling to France for an extended visit in 1801, Nathalie met Thomas Sumter Jr., a diplomat and the son of General Thomas Sumter. They married in Paris in March 1802 before returning to his home in South Carolina. From 1810 to 1821 they lived in Rio de Janeiro, where Sumter served as the American ambassador to Portugal during the transfer of the Portuguese Court to Brazil. One of their children, Thomas De Lage Sumter, was a Congressman from South Carolina.