Eileen Adeline Stewart left her Mount Nelson home on November 7, 1958, telling her husband she was going into town shopping and never returned.
The family, originally from Britain, lived at the Signal Station cottage with the father Charles operating the nearby semaphore.
On the same day his wife disappeared, Charles put their four children, all aged under 9, into two separate orphanages.
He then contacted police to report her missing.
In the weeks and months that followed, searches of Mount Nelson and beyond proved fruitless.
Police contacted relatives in the United Kingdom where the family was originally from.
At the time, Mrs Stewart's mother told London police she believed "her daughter deliberately left her husband because of his treatment of her".
The investigation was re-opened in 2014 as part of a coronial review of long-term missing persons cases.
DNA testing was conducted on unidentified bones found on Mount Wellington in the early 1970s that had been kept in storage.
Police and forensics further searched the area around the Stewart family cottage and excavated what was thought to potentially be a grave.
But coroner Simon Cooper, who investigated Mrs Stewart's death, said "none of these enquiries revealed any information to assist in the investigation".
