Hi Warren,
Some results from searching NSW BDM indexes:
NSW Justice, Registry of Births Deaths & Marriages (Family History Search) [ http://www.bdm.nsw.gov.au/Pages/family-history/family-history.aspx ]
Firstly, David's birth registration is spelled as Stoddard; all others are correct as Stoddart. David was born in Newcastle in 1887 (Registered 30949/1887)
Margaret Hathaway born in Newcastle ( 29513/1889 ) - Mother Emily (no father recorded). In 1897, Emily Hathaway married Enoch S. Porter in Merewether, NSW ( 5732/1897 ).
In 1908, Maggie H. Porter married David Stanley Stoddart in Lambton, NSW ( 5012/1908 ).
Margaret Stoddart died in Newcastle in 1956 ( 5314/1956 ); David Stoddart died in Wallsend, NSW in 1966 ( 15078/1966 ).
(On Margaret's death registration, her parents are listed as Enoch and Emily; on David's death registration, his parents are listed as David Dundas and Jessie.)
Between 1909 and 1915 (latest year available) David and Maggie had four children: Edith D., Stanley F., William D. and Dulcie.