Barbara Louisa St. John (1819-1850) (1819–1850) Parents Elizabeth Maria Barker Robert William St. John Children Henri Emilien Toussaint Dalmas de Lapérouse Léon-Robert Dalmas de Lapérouse Siblings Henry Thomas St. John Mark Kerr St. John Frederick Arthur St. John Charlotte Elizabeth St. John Emilie Diana St. John Louisa Caroline St. John Partners Théobald Dalmas de Lapérouse