Okay this is what I have been able to find.
I am sure that Mary SMITH had died by the time the 1901 Census was taken. Either that or she is hiding well
1891 Census England Huntingdonshire Yaxely
RG12/1225/96/3
Annie Street
SMITH
Joseph Head Marr 39 Gardener and Farmer Hunts Farcet
Emma E Wife Marr 36 Hunts Elton
David Son Unmarr 6 Scholar Hunts Yaxley
Joseph Son Unmarr 4 Hunts Yaxley
William Son Unmarr 3 Hunts Yaxley
Edward born 1848 ish is at home with his parents/parent until the 1881 Census.
1881 Census England Northamptonshire Paston
RG11/1592/47/15
SMITH
Edward Head Marr 33 Railway Labourer Hunts Farcet
Catherine Wife Marr 34 Cambridgeshire Thorney
Maria Dau Unmarr 6 Northants Peterbro
Edward Son Unmarr 4 Northants Peterbro
William J Son Unmarr 2 Northants Dogsthorpe
1891 Census England Huntingdonshire Farcet
RG12/1255/140/4
High Street
SMITH
Edward Head Marr 43 Farm Labourer Hunts Farcet
Catherine Wife Marr 44 Cambs Thorney
Edward Son Unmarr 14 Northants Peterbro
William Quincey Son Unmarr 12 Northants Garten End
Joseph Son Unmarr 6 Nortants Paston
David Son Unmarr 5 Hunts Farcet
1901 Census England Huntingdonshire Farcet
RG13/1459/138/3
Lane Rutland Cotts
SMITH
Edward Head Marr 52 Brickyard Labourer Hunts Farcet
Catherine Wife Marr 53 Cambs Thorney
Edward B Son Unmarr 24 Brickyard Labourer Northants Peterbro
William Q Son Unmarr 22 Brickyard Burner Northants Dogsthorpe
Joseph Son Unmarr 17 Brickyard Labourer Northants Paston
David Son Unmarr 15 Brickyard Labourer Hunts Farcet
Daisy Dau Unmarr 6 Hunts Farcet
William Visitor Unmarr 13 Hunts Yaxley
David was at home until 1881. There is a David SMITH on the 1881 Census at 21 Palmerston Road, Woodstone, Huntingdonshire. He is lodging with the HEMSBY family and his occupation is Railway Shunter Pointsman. The only thing is that he gives his birthplace as Stanground. Don't know if this is close to Farcet or not.
In 1891 he was in London, Islingon, Upper Holloway. He was living at 24 Christies Road with the WALKER family. He is listed as being married, aged 35 and a Railway Labourer, born Farcet, Huntingdonshire.
His marriage to Emma ROBINETT was in Sept Qtr 1889 Peterbro Huntingdonshire.
Here is Emma and the children in 1891
1891 Census England Huntingdonshire Yaxley
RG12/1225/82/2
Church Street
SMITH
Emma Head Marr 35 Hunts Yaxley
Mary C Dau Unmarr 5 Hunts Yaxley
Emma E Dau Unmarr 8mths Hunts Yaxley
1901 Census England Huntingdonshire Yaxley
RG13/1459/83/2
Church Street
SMITH
David Head Marr 46 G Labourer Hunts Yaxley
Emma Wife Marr 46 Hunts Yaxley
Mary C Dau Unmarr 15 Hunts Yaxley
Elizabeth E Dau Unmarr 10 Hunts Yaxley
Patience R Dau Unmarr 8 Hunts Yaxley
Frederick Wm Son Unmarr 5 Hunts Yaxley
Believe it or not Christmas is transcribed in 1891 as XMAS which made him a bit hard to find. He was with his mother Mary until 1891 :-
1891 Census England Huntingdonshire Yaxley
RG12/1225/82/1
Church Street
SMITH
Xmas Q Head Marr 36 Brickyard Labourer Hunts Yaxley
Frances Wife Marr 36 Hunts Brampton
Arthur HART Adopted Child Unmarr 1 London Philpot Lane
Cannot find them on the 1901
Will try and find the marriages for the girls in this family
Cheers
Karenlee