The Widow Married was the first sequel ever, following The Widow Barnaby (1838) and preceding The Barnabys in America (1843). It appeared serialized in The New Monthly Magazine from May 1839 to June 1840, and then as a three-volume novel by Henry Colburn and illustrated by Robert W. Buss (best known for his illustration of “Dickens's Dream”).
Alas, we are not to know much about Mrs Barnaby's first and second husbands. The last page of The Widow Barnaby suggests that Mrs O'Donagough was married for less than a year and dressed in mourning less than that before joining in blissful wedlock with Major Allen. To remedy the speedy ending of that biography, The Widow Married …
Ayres, Brenda. "The Widow Married; A Sequel to the Widow Barnaby". The Literary Encyclopedia. First published 28 June 2010
[http://www.litencyc.com/php/sworks.php?rec=true&UID=30663, accessed 20 February 2017.]