You certainly have a point Sue. Susan is 4 years, Lazarus is 2 years and Christoper 1 year on the 1841.
Perhaps Susan was not immediately registered at birth as she would be noted as 3 years of age on the 1841 census which was taken on 7 Jun 1841. Civil reg only commenced in July 1837 so perhaps not everyone was prompt in registering their offspring as they should have been. I understand it was not compulsory. I found this snippet quite interesting Originally, the registrars had to travel around and visit the people who had an event and make a note of the details. A new Act of 1874 removed this and it was up to the people to visit the local registrar office to record the event.
Births Mar 1838
POTTER Susan Ketteridge Linton 14/77
Births June 1840
POTTER Christopher Kitteridge Linton 14/71
If you do a search for a Lazarus POTTER and no other identifying data, on the 1841 census, there is only one result...the following.
1841 Census West Wratting, Cambridgeshire
POTTER, Joseph 40 Not born county
POTTER, Hannah 40
POTTER, Elizabeth 20
POTTER, James 15
POTTER, Hannah 15
POTTER, William 13
POTTER, Josiah 9
POTTER, Joseph 6
POTTER, Susan 4
POTTER, Lazarus 2
POTTER, Christopher 1 All born county except Head of house, Joseph who on the 1851 census is born Suffolk.
1851 Census does not show a younger son than Christopher. There are two grandsons James 5 years and Albert 11 months.
Hannah is aged 51 on the 1851 census...possibly her birth below as place of birth is H......., Cambridge.
KETTERIDGE Hannah
Birth 14 Apr 1798 Horseheath, Cambridge Eng.
Baptism 28 Apr 1798 Horseheath, Cambridge, Eng
Father Christopher KETTERIDGE Mother Mary
I haven't seen any online tree so can only work from the indexes and census.
South Australian Government Gazette 1859
List of unclaimed Letters at the General Post Office at June 1859
POTTER, Lazarus
Brands South Australian Directory 1901
POTTER Lazarus P 7 7
South Australian Directory 1924
POTTER Lazarus lbr Wolseley
POTTER Richard lbr Wolseley
POTTER S lbr Wolseley
I wonder about Nazareth as Walter's father on the 2nd marriage. I would suggest an error...both biblical names.
Cheers
Cando