Around the same time she began to frequent the Sun Inn on Long Millgate in Manchester, a pub popular with poets, writers, and other working class intellectuals, and became part of a poetry collective known as the Sun Inn Group alongside figures such as Samuel Bamford, John Critchley Prince, John Bolton Rogerson, Robert Rose, Elijah Ridings, and Robert Story.

[4] In the early 1860s, Isabella's eldest child died (then aged 14), and her sense of loss is believed to have inspired her to write her first novel, God's Providence House: The famous story of old Chester, which presented an absorbing story of love and adventure set in the days of highwaymen and plague around the area of Chester in Cheshire, in which one character lived on Watergate Street with "God's Providence is Mine Inheritance" written on its frontage beam, being one of the few houses not struck by plague.

[6] The book became her most lasting achievement and is considered to be an important social and historical novel, charting the rise of Jabez Clegg, the eponymous "Manchester Man", from the time of the Napoleonic Wars to the first Reform Act.

His personal fortunes, from the near tragic snatch of his crib from the River Irk, create a tale of romance and melodrama, his life from apprentice to master and from poverty to wealth, mirroring the growth and prosperity of the city.

The book is still read throughout the world (following republication in 1991 and again in 1998), and its heroes, Jabez Clegg and Joshua Brooks, are commemorated locally in the names of Manchester public houses.

[8] Anthony Trollope greatly admired Isabella Banks's contribution to literature, and is reported to have observed that her "reward in literary life had fallen short of [her] deserts".