She is also eternally grateful to all those people who searched.

“We are overwhelmed by the generosity and time spent to help find her. We will be forever grateful,” Ms Pellegrini said.
 

Ms O’Pray was a healthy, active woman who loved walking. She had two regular routes – from Medlow to Katoomba along the shared bike track and Grand Canyon Road towards the air field.
 

It was thought that it was the latter path Ms O’Pray took on March 7 but both areas were repeatedly searched for 14 days.
 

“It was massive,” Ms Pellegrini said. “Police told me it was unprecedented.”
 

The helpers included NSW Police, NSW Police Rescue, Polair, RFS, SES, Volunteer Rescue Association, NSW Police Dog Squad, NSW Ambulance, Westpac Helicopter, Bushwalkers Wilderness Rescue Squad and Cave Rescue.

“In particular I would like to thank Dallas Atkinson, Steve Day, Inspectors Scott McAlpine and Sonya Tabor and Superintendent Darryl Jobson, plus all the community members who organised their own groups and searched, not attached to any organisations, just lovely local people.”

Ms Pellegrini said she, her husband Michael and their three daughters were all still in shock that Ms O’Pray was gone.
 

Her four-year-old was often in tears, saying she missed her nanna.
 

“We’re all still really depressed and anxious just to get some answers, just to get a bit of closure.
 

“We’re all realistic – no one could survive this length of time. I know that the outcome is not going to be great. We’re at peace that she’s passed but she still needs to be found and laid to rest.”
 

Ms O’Pray migrated to Australia from Scotland when she was 22. She worked as a governess on a cattle station in Queensland and later as a dance instructor at Arthur Murrays, where she taught ballroom and Latin American.
 

“She was a great dancer,” Ms Pellegrini  said. “She also loved music and I would often arrive at her house to see she had the music blaring and was jiving around the house as she did the housework.”
 

Ms O’Pray raised Kate, an only child, on her own and the two were very close. Ms O’Pray moved from Bullaburra to Medlow Bath in 2012 to be closer to her daughter and her family.
 

“She loved to spend time with her grandchildren and spoilt them as often as she could.”
 

Ms Pellegrini said her mum was in good health and, contrary to media reports, didn’t suffer from dementia.
 

Superintendent Jobson said the search was one of the largest of its kind.
 

“Over 1500 personnel were involved covering an area of about 25 square kilometres with the aerial search covering about 50 square kilometres.
 

“Day after day they had about 150 searchers, mainly volunteers from the RFS, SES and VRA.
 

“The volunteers did a remarkable job traversing difficult terrain and their commitment to finding Ms O'Pray is a credit to themselves and the organisations they represent.”
 

He thanked all volunteers as well as his officers for their efforts.

But, despite the efforts of hundreds of volunteers, 77-year-old Betty O'Pray was never seen again.
 

At an inquest into her disappearance in Katoomba in February, the coroner heard that police rescuers spoke to Ms O'Pray on her mobile phone 24 hours after she disappeared but she was unable to tell them where she was.

And efforts by Optus to locate her through her mobile pointed volunteers in the wrong direction, the court heard.

Counsel assisting the coroner, Robert Ranken, outlined Ms O'Pray's last movements and phone calls as rescuers desperately tried to find her.

Mr Ranken said Ms O'Pray was a regular walker, often doing the 10-kilometre return trip to Katoomba or heading east from Medlow Bath along Grand Canyon Road towards the air strip or out further to Point Pilcher Lookout, a distance of some 17 kilometres return.
 

She set out some time that afternoon, with witnesses seeing her on the highway near the Mazda outlet and CCTV footage from the United service station catching her heading towards the railway station.
 

From 4.30pm onwards, her daughter, Kate Pellegrini, repeatedly tried to call her mother. She scoured the streets around her home in Delmonte Avenue while her husband, Michael, walked the track from Medlow to Katoomba hoping to find her.

At 11pm, Ms Pellegrini reported her mother missing to Katoomba Police, who checked the hospital and CityRail CCTV, Katoomba CBD and nearby areas.

By 7 the next morning, Sergeant Dallas Atkinson, a veteran of hundreds of search and rescue operations with Police Rescue, was setting up a land search, with police, RFS and SES volunteers.

At 5.15pm, Ms Pellegrini tried her mother's mobile again and was surprised when it was answered. Her mother said she was lost, she knew people were looking for her as she'd seen the helicopters overhead, but she couldn't say where she was. And her phone battery was nearly dead.
 

Ms O'Pray had an old Nokia phone which was not equipped with GPS, Mr Ranken told the court. Efforts were made using location-based services to triangulate her position, suggesting her phone was pinging off a mobile tower in Valley Road, Katoomba, near Narrow Neck Road.
 

"Most likely that information was incorrect," Mr Ranken said.
 

Sgt Atkinson also spoke to Ms O'Pray, keeping it brief to conserve battery life. He said a helicopter would soon be flying over and when she saw it, she should ring him so they could pinpoint her position.
 

She never rang.

Twice more that night, Sgt Atkinson received calls from Ms O'Pray but heard only rustling. He presumed they were accidental "pocket" calls.

At 10.43pm Sgt Atkinson called again - the phone rang twice but then stopped. The battery was dead and contact had been lost.

Over the next week, hundreds of volunteers joined the search, scouring areas of South Katoomba, Radiata Plateau, Nellies Glen and the Six Foot Track.
 

But Sgt Atkinson had grown increasingly concerned about the triangulation - logs of Ms O'Pray's phone contradicted the co-ordinates Optus had given.
 

By March 13, a week after she disappeared, Sgt Atkinson consulted a doctor with expertise in survivability who said dehydration, exhaustion and Ms O'Pray's hypertension almost certainly meant she was dead. He gave her only a 5 per cent chance of being alive at that stage.
 

Notwithstanding that, search efforts continued across a number of areas. But no trace was ever found of the Scottish born former dance teacher.
 

Mr Ranken said Ms O'Pray had been an active woman, although she had suffered a mild stroke in 2012. There had also been two occasions in 2015 when she was found disoriented.
 

But her doctor, who last saw her in 2015, concluded she was an "elderly but vibrant lady with a good sense of humour". 

The deputy state coroner, Derek Lee, will have to make a finding as to whether Ms O'Pray is dead and, if so, the likely time and place of death. He will also consider how or whether police were adversely affected by the information from Optus.