Davie's disappearance continued to affect the family, said her brothers Peter and Nigel Davie.
"You don't think about it every day but often something will happen and you'll think of her and wonder. But you have to carry on," said Peter Davie.
Nigel Davie said his sister's disappearance had a huge effect on their parents Tom and Merle, who have since died. "It did really affect them because she was the only daughter. Mum never got over it," he said.
Detective Sergeant Robert George of New South Wales said the case remained an "open wound" for the family.
Police hoped the release of the images would also encourage a witness from 1980 to come forward. The person, believed to be a New Zealander, contacted the police and claimed to have seen a female matching Davie's description on a flight from Sydney to Christchurch on April 7, 1980.
The night before she disappeared, Davie and a friend met the two men featured in the images released by police at a nightclub at Kings Cross. They later gave her a ride home.
There was no information to implicate either male, but because of their involvement with Davie before her disappearance they may be able to provide more information about that night, said police.
When Davie's flatmates came home they found her bed had not been slept in and her possessions were untouched.
Three days after he last saw her, Lavender received a letter from Davie saying she would be away for a few days. Police believe the letter may have been forced.
In the 31 years since she disappeared, there had been no leads about what happened, said George.
