It looks like Harriet Mary Eliza SAMPSON (b. Est 1796; d. 1849) on 2 Jan 1812 at Christ Church, Newgate, London, married James SLEIGH (b. 14 Sep 1788 London; d. bef. 1817).
Harriet (on 12 Feb 1822) gave birth to the, I think,illegitimate Elizabeth (thus the "father unknown" on the b/c; and hence she got the "SLEIGH" surname). Perhaps George KENNIWELL was her natural father.
On 23 december 1822, Harriet married George KENNIWELL and Elizabeth was given the surname "KENNIWELL".Edward SLEIGH (b. 31 March 1813, Holborn Lying-in Hospital, Endell Street, London; d. ???? hunter Valley ??) would thus have been Elizabeth's half-brother.
The above relates to a musing in my posting; it's the LAYTHORNs and LATHAMs I'm trying to sort out.