Witnesses to the marriage were William and Martha West.

Benjamin was a 26 year old bachelor and Lucy, a 29 year old spinster, both from Swerford parish.

Lucy's parents were John (1790-1868), a labourer and Hannah Pratt (1800-1866).
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The 1861 census shows the following at Swerford, Chipping Norton District, Oxfordshire, England
ANNIS, Elizabeth 37 F Chipping Norton
ANNIS, Frederick 1 M Chipping Norton
ANNIS, Hannah 60 F Chipping Norton
ANNIS, John 73 M Chipping Norton
ANNIS, Lucy 22 F Chipping Norton
ANNIS, William 37 M Chipping Norton

John and Hannah were Lucy's parents. William was her older brother, but I'm not sure who Elizabeth Annis was.
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The 1871 census for Oxfordshire and North Berkshire shows Lucy as living at Blue Row, Swerford with her husband Benjamin's cousin William Knibbs and his wife Emily. Lucy's son Frederic is living with her. Her husband Benjamin had died in 1869.
Lucy E KNIBBS 29
Frederic 12
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The 1881 census shows Lucy as living at Wigginton, Oxfordshire with her third husband Edward Walden, and 5 of her 7 children. They are listed under Cottage, Wigginton, with the surname of Walker. I am fairly confident that Walker is a transcription error for the census. All marriage, baptism and burial records are given as Walden.
Edward Walker head gen lab aged 29 born Wiggington
Lucy Walker wife gen lab wife aged 39 born Swerford
Ann Knibb stepdaur scholar aged 10 born Wiggington
Sarah E Walker daur scholar aged 7 born Wiggington
Ellen J Walker daur scholar aged 4 born Wiggington
William G Walker son scholar aged 3 born Wiggington
John Walker son 2 months born Wiggington