there is a tree on A* with info that matches yours but has a second marriage for James in Hobart to Mary Cairns 1863. is this the same person?
of so has his bap as 27/2/1802 london s/o henry Banks & Ann Rug
also only one child given = William 1851??
think it is them as 1851 census given in Bermondsey surrey has:
James Banks 31 shoe currier b.Bethnal Green,Middlesex
Ann Banks 28 b.Lambeth
Ann L Banks 8 b.Town Mallins,kent
Jane E Banks 6 b.southwark,surrey
Emma Banks 4 b.Newington,Surrey
James W Banks 2 b.newington,surrey
Diddy Beat me to it!!!