There are two baptisms to be found within 10 miles of Ruardean, Glos:

Hannah Bennet dau of John and Margaret Bennet at St Mary, Monmouth, Monmouths on 28 Jun 1818.

Hannah Blenett dau of Samuel and Betty Blenett at Blakeney, Glos on 10 Jul 1820.

I don’t think either of these are hers so cannot identify her parents.  Remember, though, that her marriage certificate would include her father’s name.
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Her death index, almost certainly:

First name(s)  HANNAH
Last name      KNIGHT
Gender         Female
Birth year     1817
Age            65
Death quarter  1
Death year     1882
District       Westbury on Severn
County         Gloucestershire
Volume         6A
Page           171
Country        England
Record set     England & Wales Deaths 1837-2007
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Their marriage index:

First name(s)     RICHARD
Last name         KNIGHT
Marriage quarter  3
Marriage year     1837
MarriageFinder    RICHARD KNIGHT married one of these people
                  Hannah Bennett, Fanny Duberley, Sarah Griffiths, Elizabeth Dean
District          Ross
County            Herefordshire
Country           England
Volume            26
Page number       271
Record set        England & Wales Marriages 1837-2005
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No church marriage found.  Perhaps this was one of the first tegistry office marriages?  The Marriage certificate would answer that.