COMPLETED WITH THANKS missing family 1871 census - help please

[sueky71]

i'm trying to find my grt grandmothers family. 
so far i have them on the 1861 census in buckinghamshire as: william beckwith (33), wife selina (29) and 2 children emily (2) & amelia (6m).
i also have them on the 1881 census in cheshire as william (57) selina (49) & children minnie (18) mary (16) john (14) and anna (11).
in the 1891 cheshire census i have william (63) selina (59) minnie (28) & grandchildren lilly (6) and william (13).
william was born in staffordshire, whilst selina and all their children were born in buckinghamshire. the grandchildren were born in cheshire.
i can't find sign of them on the 1871 census, despite trying various spellings of their names.
any help greatly appreciated 

[Manchester Rambler]

RG10; Piece: 3709; Folio: 48; Page: 37
24 Oakley St, Monks Coppenhall, Cheshire

William Beckwith - Head - 42 - Engine Fitter - Handsworth, Staffs
Selina Beckwith - Wife - 39 - Shenley, Bucks
Clara Beckwith - Dau - 14 - Scholar - Stantonbury, Bucks
Elizabeth Beckwith - Dau - 10 - Scholar - Stantonbury, Bucks
Minnie Beckwith - Dau - 8 - Scholar - Wolverton, Bucks
Mary Beckwith - Dau - 6 - Scholar - Wolverton, Bucks
John Beckwith - Son - 4 - Scholar -Wolverton, Bucks
Anne Beckwith - Dau - 1 - Wolverton, Bucks

Rambler

[sueky71]

ooooh manchester rambler you are a star
thank you very much
  *big hug*