Essex Record Office ref: West Mersea D/P 77/1/6 baptisms:
Page Year M & day Child's name Parent(s) Occ
5 1814 July 31 Sarah Willm and Mary Cooper
SHEPHERD
36 1825 Jan 30 William Susan SHEPHARD BB born 29 Aug
1824
They were the only SHEPHERD baptisms I saw between 1814-1825. I went to look at marriages in West Mersea. I did not have time to look at the primary documents. Instead I went to a very reliable modern transcript - Essex Marriage Register Vol. 84
page Year M & day
5379 1823 Oct 29 COOKE James m SHEPPARD Sarah (SHEPPERD
in place for signature)
5373 1803 Mar 7 SHEPARD William m HOWARD Mary widow
They were the only SHEPHERD marriages in West Mersea that I saw and I think I searched that Volume from 1782-1851. I also searched East Mersea marriages Vol 84 pp 5361-5363 (a much smaller population) 1801-1837 and saw none at all there.
So I went back to West Mersea baptisms looking for COOKs and found these
45 1828 May 18 Rebecca of James and Sarah COOK mariner
48 1829 Sep 6 Willm of James and Sarah COOK mariner
55 1831 May 21 Eliza Longstaff of Willm* and Sarah COOKE mariner
60 1833 May 26 Sarah of Willm* and Sarah COOKE mariner
63 1834 Aug 3 Mary Ann of Willm* and Sarah COOKE mariner
68 1836 May 22 George of Willm* and Sarah COOKE mariner
I finished searching at page 73 (1837).
One more thing - the asterisks above indicate that written above father William's name was another name. It looked like 'Eliza' but I suppose it must be intended to be 'Elija'? Unless you know differently