Hi John,
These are from the Kilsby registers:
Mary d James & Sarah PETTIFER of Kilsby, labourer, bapt 24 Mar 1816
John s James & Sarah PETTIFER of Kilsby, labourer, bapt 13 Dec 1818 (bur 4 Oct 1822 age 3)
Joseph s James & Sarah PETTIFER of Kilsby, labourer, bapt 5 Aug 1821 (bur 21 Dec 1826 age 5)
Clemence s James & Sarah PETTIFER of Kilsby, labourer, bapt 25 Jan 1824
William s James & Sarah PETTIFER of Kilsby, labourer, bapt 13 May 1827
James s James & Sarah PETTIFER of Kilsby, labourer, bapt 13 May 1827.
Couldn't find a marriage for this couple in Kilsby but I did find a marriage for a James PETTIFER and Sarah CROSS on 22 Oct 1815 at Rothersthorpe (both of this parish).
There were no Pettifers in Kilsby in the 1851 census index and I couldn't find James or Sarah in the county at that time.
Regards
byron