Regarding your grandmother, in the 1901 Middlesbrough, Yorkshire census, I found Sarah J. Luthwaite, niece, single, age 17, general servant – domestic, born Middlesbro’, Yorks, living in the household of Thomas M. and Margaret A. Johnson.
Sarah Jane Lewthwaite married Edward Cranmer in the April-May-June quarter of 1904 in Middlesbrough.
1911 Middlesbrough, Yorkshire census
Edward Cranmer, head, 29, married, married 7 years, brass molder at Livingstones Foundry, born Sunderland, Durham
Sarah Jane Cranmer, wife, 24, married, 4 children born – 3 living – 1 deceased, born Middlesbro’, Yorks
Lily Cranmer, daughter, 5, single, born Middlesbro’, Yorks
Dorathey Cranmer, daughter, 3, single, born Middlesbro’, Yorks
Edward Cranmer, son, 5/12, single, born Middlesbro’, Yorks
Margaret Lewthwaite, sister-in-law, 18, single, general servant – domestic, born Middlesbro’, Yorks
Regarding your great-grandmother, here is a possiblity:
1871 Framwellgate, Durham census
William Sweeting, head, 50, cart man, born Yorkshire
Martha Sweeting, wife, 37, born Durham
John Sweeting, son, 15, born Durham
Elizabeth Sweeting, daughter, 12, born Durham
William Sweeting, son, 9, born Durham
James Sweeting, son, 3, born Durham
Martha Sweeting, daughter, 1, born Durham
John Devlin married Martha Sweeting in the April-May-June quarter of 1887 in Middlesbrough (volume 9d, page 830). IF, this is your correct great-grandparents, this would be a good marriage record to have, because if would include the name and occupation of the father of both the groom and bride.
My Devlins ended up in Ontario, Canada.