From Ancestry Select Marriages:
Sarah Hale Kane, 18 yrs (1854) Father William Kane
Thomas Hedderly, 24 yrs (1848) Father William Hedderly
Christ Church, Newcastle upon Tyne
13 Nov 1872
1871 cen
Sarah Cain, 14 (1857) Servant, birthplace Not Known
Civil Parish Corenside, Bellingham, Kirkwelpington, Northumberland in the home of John Nesbit.
RG10; Piece: 5159; Folio: 23; Page: 12
It could be she didn't know where she was born, or she was not asked and someone else gave the details.
b.