Took a swing, but not helpful. Sorry.
The Smith child, if young enough, may not have been reported. There would have to be some family record of the stillborn birth, if the child existed. They would have had to of been having children in very close succession.
18 Aug 1867, 1869, 8 May 1870,(19mths) 31 Dec 1871,(20mths) 17 Sep 1873,(18mths) 31 Mar 1875,(16mths) 14 Aug 1876,(31mths) 21 Mar 1879,(19mths) (2 Nov 1880),(12mths) 24 Oct 1881, (11 Apr 1885), 21 Mar 1886.
As already pointed out. Sorry to repeat. (NSW BDM Deaths, TAPP MARGARET E, 6381/1880, WILLIAM, ELIZABETH, DENILIQUIN)