In the 1871 census, Robert and Jane's youngest children, ( John T and Jane) are shown as being born in Cockfield and all are living in Cockfield, But we can't find them in the 1891 and 1901 census,
Hi rayaco

I did in fact tell you where they were living in Kimblesworth in 1891 and 1901 in reply 21

1901 census
RG 13 / 4676 / 119 / 11
37 John Street, Kimblesworth
John T. Atkinson, head, s, 35, Cashier at coal mine, Durham Cockfield
Mary do, sister in law, m, 47, do Bildersham
Robt do, nephew, s, 21, Supt on cleaning belts mine, dp Kimblesworth
1891 census
This has to be the same family, living at the same address (where Robert died in 1889
*) despite the incorrect place of birth
RG 12/ 4100 / 81/ 9
37 John Street, Kimblesworth
John T Atkinson, head, s, 24, cashier, Durham Staindrop
Jane do, mother, wid, 59, do do
Jamesw do, brother, s, 19, clerk, do do
Staindrop is in fact only about 3 miles south of Cockfield where John was born.