I just received some information from the Dalby Family History Society, PO Box 962, Dalby, Qld, 4405.
Hazel Shirley Cortes had six siblings - the only name so far found in the limited research of $20.00 - is Noel Charles Cortes born c 1933 at Dalby.
Their parents Charles Noel Cortes and Mary Margaret Olive McKeon married 1924 at Toowoomba, Qld. Charles died 13 Dec at Toowoomba and Mary (known as Margaret) died 26 Aug 1941, Dalby, Qld. Charles is buried at Drayton & Toowoomba Cemetery.
From Electoral Rolls - Charles and Mary - 1934-1949 lived at Matheson St Dalby, Charles was a labourer. 1959 Charles lived at Yaralla St and 1962 at Etty St, and was a railway ganger.
From his obituary, Son Noel Charles (aka Dick) died 26 May 2007 at Dalby, married (1) Noela May (maiden name not known as yet) (2) Val (maiden name not known). He was father and father in law to Garry & Bev, Karen & Maurice, Pauline & Robbie, John and Trina, Sue and Bill, Richard & Max, Tony and Caroline, Glen and Antoinette, Stepfather to Tracy, Ronald, Maureen, Doris, Denise and Trevor.
If you want a further search you might like to contact the Dalby Family History people. Let me know what you find if you do.