As Sandi enquired about on the NZ board:
Muss suggested an online family tree which had the parents of Violet as Robert and Amy.
38146/1907 Violet L Graham parents ROBERT and AMY F NEWTOWN
Marriage: 2635/1906 Robert GRAHAM to Amy F THOMPSON WATERLOO
Death of Amy, as suggested by online tree:
4017/1944 Amy Florence Graham 59 YRS NEWTON
Funeral notice:
http://nla.gov.au/nla.news-article17874545Rookwood: AMY GRAHAM 59 8-1-1944 Area:Zone D Section:15 Grave: 1893. No headstone inscription.
Gladys is at Rookwood Catholic and no headstone inscription:
Section Grave Mortuary 2 Area: 10 Grave : 1428 1-1-1925 age 19.
Jamjar
Added: This is only a wild guess, based on the fact that Robert had a daughter named Clarice Mary Ann and a son Archibald Robert:
GRAHAM ROBERT
11322/1956 Robert GRAHAM parents ARCHIBALD and MARY JANE NORTH SYDNEY
GRAHAM Robert Death notice 20-4-1956 Death 76 at Royal North Shore Hospital Sydney Morning Herald 23-4-1956