Strange?!

I found this marriage on Cornwall-OPC-database:
18th September 1856 at Bodmin
John Davis, 31, Bachelor, Barrister's Clerk, of Pump Court, Temple, London
Adelina Sibly, 22, Spinster, Dressmaker, of St Nicholas Street
Fathers: John Davis (deceased), Barrister's Clerk and Richard Sibly (deceased), bookseller
Sure enough, she is on the 1851 census:
Reference HO107, Piece 1904, Folio 388, Page 44
St Nicholas Street, Bodmin
Sibley, Mary Head Widow F 52 Annuitant b Bridport, Dorset
Sibley, Adalina Daughter F 17 Dress Maker b Bodmin
However, Adelina & John Davis are in London in 1861 and 1871!