It looks as though Sarah Hannah Saull married as Hannah Saul for in the GRO marriage indexes there is a marriage between a Hannah Saul and Joseph Sanders in the June 1849 quarter in the St James Westminster registration district. Is this the correct marriage and do you have a copy of the certificate?

A Sarah Hannah Saull was baptised on 24 October 1824 at St Matthew, Bethnal Green, London to William and Hannah Saull. I have taken this information from the IGI and the entry also records that Sarah Hannah was born on 7 September 1824. It is possible that they also had other children and possibly may be the parents of a William James Saull baptised on 11 March 1827 at St James Westminster.

Do you have any further information that may help to identify what became of William and Hannah?