I wonder if this is a clue from 1901 census?
3 Bell Yard, Croydon
George Fitsall 32 Fish Curer Hatcham, London
Johanna Fitsall 32 Peckham, London
George Fitsall 12 Peckham, London
Edward J Fitsall 8 Croydon
Mary Fitsall 6 Croydon
Johanna Fitsall 2 Croydon
John Fitsall 2 Croydon
12 in 1901 would make him 29 in 1918, right age to father a child.
By 1911 this George is married and living in Camberwell, I think he dies 1955.