Isabella Letitia St. John (born 1816) (b. 1816) Parents Maria St. John-Mildmay Henry St John, 4th Viscount Bolingbroke, 5th Baron St John Children Emily Isabella St. John Horlock Siblings Anne Jane Charlotte St. John Maria Louisa St. John Henry St John, 5th Viscount Bolingbroke, 6th Viscount St John Emily Arabella Jane St. John Spencer Mildmay St. John Partners Frederick Geldart Webbe Horlock