Just looking at the
1891 census 1901 census and there only seems to be on William R Stevenson but this one is born abt. 1887 and he is born in Collierley, Durham.
RG13/4666/94/page 45
Perhaps this is them - if so they are living with their son in law and presumably a daughter, Edward & Mary Oliver and their 3 children
John Stephenson, father in law, age 54, Mason's lab., born Ovingham, Durham
Christiana Stephenson, mother in law, age 51, born Collierley, Durham
Robert Stehenson, son, brother in law, age 27, Mason's lab., born Collierley
William R Stephenson, brother in law, age 14, born CollierleyWelcome to RootChat

Maggie
(correction on year of census - apologies for any confusion I may have caused 
)