Jeez, how complicated does this family get! So it looks like Sarah was a full daughter of William & Frances Sarah:
HURRICKS, SARAH mmn STUTTLE GRO Reference: 1853 D Quarter in ST MARY NEWINGTON Volume 01D Page 172
According to a tree, the children with William & Caroline in 1871 were born as Checketts, which is the surname of the neighbour Caroline from 1861!
CHECKETTS, STEPHEN JAMES mmn MORRIS GRO Reference: 1863 J Quarter in NEWINGTON Volume 01D Page 207
CHECKETTS, ALFRED mmn MORRIS GRO Reference: 1865 J Quarter in NEWINGTON Volume 01D Page 222
CHECKETTS, ELIZABETH mmn MORRIS GRO Reference: 1868 S Quarter in NEWINGTON Volume 01D Page 212
My first thought was that [Frances] Sarah left William for his brother, Henry, but with the 1861 showing them as BERRY, who knows!.
Caroline's husband Charles Halford Godfrey Checketts apparently died in Melbourne, Victoria in 1896.
I hope you have a good stock of paracetamol

