I note the baptism you mention on freereg but I think you have made an error on the parents year of birth. Going by the ages at death I think you mean't to Type 1781.
William ELPHICK Baptism 05 Apr 1818 Sussex Hastings : All Saints : Parish Register
Is this the parents marriage?
Harriet GUPPY to William ELPHICK Marriage 28 Mar 1807 Sussex Brighton : St Nicholas of Myra : Parish Register
Other children baptised Hastings.
Mary 4 Jul 1813, Hannah 9 Apr 1815, Emma 18 Aug 1816.
Colin