There are 3 titles associated with this person.

St. John, Isabella. Wedded Life In the Upper Ranks. The Wife and Friends, and the Married Man. In Two Volumes. London: Henry Colburn and Richard Bentley, 1831.
St. John, Isabella, and Miss E. H. M'Leod. Geraldine Hamilton; Or, Self-Guidance. A Tale. In Two Volumes. London: Richard Bentley, 1832.
St. John, Isabella. Mrs. Cleveland, and the St. Clairs, &C. In Three Volumes. London: Richard Bentley, 1836.