Looks to me it is the right Catherine in 1911 Census.
This seems to be John in 1881;
John Spencer, 29, Head, Mar, General Labourer, born Yorkshire
Elizabeth Spencer, 29, Wife, Mar, born Willington Quay, Northumberland
Isabella Richardson, 10, Step Daugter, born Willington Quay
JOHN Richardson, 7, Stepson, born Willington Quay
Walter (A. Scott) Spencer, Son, born Willington Quay
Marriage Reg;
Elizabeth SPENCER, March 1876, Tynemouth, 10b 318
John SPENCER on same page
I can see the possible George Richardson/Elizabeth Scott Marriage Dec 1871
And a possible Death Reg for George Dec 1875 Tynemouth age 44
As John Richardson was only young when his Father died getting his name mixed up on M/C may have occurred.