Alarm bells started ringing as soon as Gillian Hallac walked into her mother’s home on a Friday almost six months ago. Having not heard from her mother, Yvonne Whear, since the day before, Hallac went looking for her at the 73-year-old’s hobby farm on the outskirts of Dungay, a small town near the NSW-Queensland border.

Whear is a private person most comfortable in the company of her animals, but kept in almost daily contact with her close family; to have not heard from her for almost two days uncommon. More unusual was the state of her mother’s home when Hallac arrived; she found her mother’s boots by the door, and the hat she had been wearing the day before lying on the floor, but there was no sign of Whear.

The most alarming thing about Whear’s absence, though, was her animals. Whear loves her ducks, chickens, dogs, rabbits and cats deeply; next to her family, they are all she has, Hallac says. “She would never willingly leave her animals without arranging for their care or stop contacting her family,” Hallac says. But that day, they’d been left to fend for themselves. Hallac’s attempts to contact her mother were fruitless, as were frantic efforts to find any indication of where she may have gone. Her mobile phone was gone, as was her car. Yvonne Whear had simply vanished.

Whear was last seen on February 19, when CCTV cameras captured her driving north on Queensland Road at Murwillumbah towards her farm about 3.20pm. Data extracted from her mobile phone reveals she used the device to watch YouTube videos that afternoon, and just before 5pm, checked her voicemail. Whear’s phone pinged off a tower Dulguigan – an area neighbouring Dungay – just after 10am on February 20, and has not been detected since. “It has been almost six months now since we knew that Mum was alive and well doing the things that she loved,” Hallac says.

Initial investigations centred around the possibility that Whear had met with misadventure while driving on one of the many treacherous roads that snake through the Northern Rivers and surrounding regions in the state’s north. But searches of ravines, valleys and dense bush uncovered no signs of Whear or her vehicle, a gold Ford Escape.

Drones and helicopters have extensively searched for Whear from above, while police divers have scoured the Rous and Tweed rivers for any sign of her. The search has extended as far east as Fingal Head, just south of Tweed Heads.

“The pain of not having these answers here is well known to Yvonne’s family,” Missing Persons Register manager Detective Inspector Paul Fenwick said during a renewed appeal to find Whear on Monday.

Whear was engaged in a long-running dispute involving the lease agreement over the beloved farm she has rented for 23 years. She was due to appear in the NSW Civil and Administrative Tribunal the week after she vanished. There is no suggestion the proceedings are related to Whear’s disappearance, nor is anyone involved in them accused of any wrongdoing.

Hallac said despite the legal proceedings, which remain ongoing, Whear had no reason to suddenly leave her life behind; the beloved mother and grandmother was in good spirits, was working in disability support, and had taken up an art course at TAFE, where she was expected the morning after she vanished. “She had a life with plans and responsibilities and people who loved her,” Hallac said. “We don’t believe she had any ordinary reasons to leave the property that evening.”

Whear’s family believe the 73-year-old was taken from her home and may have met with foul play. The family, Hallac said, believes her car has been hidden by whoever was involved in her disappearance, which remains the subject of ongoing investigations. “I strongly believe that there are people out there who know more than what they have been saying,” Hallac said.

In the months since she vanished, Whear has missed family celebrations and milestones, including the birth of her first great-grandchild. Her disappearance has left a gaping hole at the centre of her family, which is desperately searching for closure. “It’s just indescribable,” Hallac said. “She’s there one day and all of a sudden there’s no her, there’s no car, there’s no answers.”

The nights since February 19 have been long and sleepless for Hallac and her family. Without answers, she said, it has felt as if life had been out on hold. She hopes Monday’s renewed appeal will bring not only closure for her family, but the truth for her mother.

“Please don’t let my mother Yvonne be forgotten. Please keep asking what happened to her. We need to know the truth. We need to know where she is and what happened to her. I believe that someone out there knows something, and they can give us the answers we need,” Hallac said.

“Whatever has been hidden in the darkness will eventually come to light.”

Anyone with information that could assist police is urged to contact Crime Stoppers on 1800 333 000.