All hospitals in the area, including Rotorua, were checked but she'd not been seen at or admitted to any.
The coroner also heard Miss Sowerby, described as a meticulous, organised person to the extent of having obsessive compulsive disorder, had booked a seat on a bus from Taupo to Orewa on New Year's Day 2004, reserving accommodation at a backpackers' there. She had also booked herself onto a bus leaving Auckland for Rotorua on January 14.
When she disappeared Miss Sowerby, an invalid's beneficiary, had been staying with a friend, John Gollan, and a woman friend of his at the Turangi Leisure Lodge where Mr Gollan had a timeshare unit.
Detective Sergeant Neale Saunders who re-investigated her disappearance some years after she vanished, said Mr Gollan's friend and Miss Sowerby did not get along.
He said investigations after Ms Sowerby's disappearance indicated she had been told she could no longer use the timeshare which had upset her because she saw it as her last link with Mr Gollan's father who had been a close friend.
Mr Saunders gave evidence that Miss Sowerby was on medication to control depression but had told friends she had switched to herbal remedies and would be off the anti-depressants by the end of December.
Referring to the day Miss Sowerby disappeared, Detective Saunders said the last time she was seen was when she left her cousin's Turangi home at 8pm on December 24, 2003. Although she had been given the alarm clock she asked for, she forgot to take it with her.
She had indicated she might walk along the Tongariro River bank to get back to the timeshare but subsequent searchers of the area found no trace of her being there or in the river.
Questioned by Dr Bain, he said there had been many theories about what happened to Miss Sowerby but nothing to suggest she had taken her own life.
Ms Sowerby's disappearance had been revisited and new techniques used in 2010 but again no evidence to suggested what happened to her had been found, Mr Saunders said.
Miss Sowerby's nephew, Mark Sowerby of Auckland, described his aunt as a lovely, caring woman who, at the time she disappeared, was travelling around the country visiting her nieces and nephews which was her custom at that time of year.
"It is strange that in Turangi you can go missing and not be found . . . it is pretty clear she is no longer with us," Dr Bain said.
"But we don't know where or why unless someone absconded with her."
He said his reserved decision would say the evidence presented suggested she had died and told her family his meant they would now be able to obtain a death certificate for Ms Sowerby which would help them get on with their own lives.
