Are we saying the Sarah (born Herts) that David Adams is "married to" in the 1871 census is not Sarah Green? I don't see any evidence of a marriage 1861-1871 so do they tell fibs

the age of Sarah through the census 1851-1871 is interesting 1851=37, 1861=40, 1871=40

Sarah, how could you!
1874
June qtr 1874, Bethnal Green R.D
Sarah Green marries David Adams
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1871 census
10 Maryland Street, Stratford, West Ham, Essex
David Adams.....Head....37.......excavator..........Weeley, Essex
Sarah......".........Wife.....40.................................Herts, Hertfordshire
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1861 census
Clacton Road, Weeley, St Osyth, Tendring, Essex
Sarah Green.....Head....40 Widow....Laundress & Lodging.....Wales
John........".........Son......16....Agricultural Labourer...............Weeley, Essex
Octavious "........Son......13....Agricultural Labourer...............Weeley, Essex
Ann..........".......Daur......11....................................................Weeley, Essex
Jane.........".......Daur......5......................................................Weeley, Essex
David Adams...Lodger....26 Unmarried.. Woodmen.... Weeley, Essex
(David Adams is stated as being 8 years old in 1841 Weeley, Essex)
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1858
Mar qtr 1858, Tendring R.D
Robert Green dies
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1851 census
Heath, Weeley, St Osyth, Tendering, Essex
Robert Green....Head...50......Ag Lab....................Ardleigh, Essex
Sarah........".......Wife....37.....................................Bracknock, Radnorshire
John.........."........Son......6......Scholar....................Weeley, Essex
Octavis......"........Son......4......Scholar....................Weeley, Essex
Sarah A.....".......Daur......18 months......................Weeley, Essex
William Syrett...Lodger...77 Widr...Pauper Ag Lab...Lt Bentley, Essex
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1844
Mar qtr 1844, West London R.D
Sarah Watkins marries Robert Green
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1841
Dec qtr 1841, Tendring R.D
Elizabeth Green dies
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1841 census
Heath, Weeley, Tendring, St Osyth, Essex
Robert Green.......45............ag lab...............Essex
Elizabeth.."..........50.....................................Essex
/
John Deeves........15.....ag lab.....................Essex
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Bryant