Ciara Glennon had been back in Perth a fortnight after spending almost a year off work travelling when she was either abducted or lured from the affluent suburb's entertainment strip, killed then dumped in bushland in 1997.

Workmate Abigail Davies, 48, said their law firm Blake Dawson Waldron had St Patrick's Day drinks in the boardroom on March 14 and a small group ended up going to the Continental Hotel, driven by their boss.

"Ciara was umming and ahhing about whether she would come and unfortunately she decided to come," Ms Davies told the Supreme Court trial of accused serial killer Bradley Robert Edwards on Thursday.

Ms Glennon was her usual gregarious and personable self and excited because her sister was about to get married and she was head bridesmaid.

"She appeared relaxed and happy," Ms Davies said.

She said they held hands as they weaved through the pub crowd, then Ms Glennon "wandered off" for about 20 minutes and later chatted with a group of about five people Ms Davies didn't know.

She briefly rejoined her colleagues then left on her own about 11.45pm.

"She just said to me 'I'm going'. She moved away from the group without really saying goodbye as such.

"She was exuberant ... she was drunk but she was very in control of everything about her person."

In a statement, Una Glennon, 71, said her daughter hadn't returned home when she went to bed and she became concerned when she woke at 3am, looked into her room and saw she was still not back.

"I reminded myself that Ciara was a 27-year-old woman who had just travelled around the world and she shouldn't feel the need to inform her parents of her every movement," she wrote.

Denis Glennon, 74, was not unduly concerned when he realised his daughter did not return home that night.

But after Ms Glennon's friends were called and it emerged she had gone to the Continental, her parents became increasingly worried, with the father abandoning a Rottnest Island trip.

Jane Rimmer, 23, was last seen at the same hotel in 1996 and Sarah Spiers, 18, vanished from the area earlier that year.

Mr Glennon, who has consistently attended the trial, spoke with his daughter over the phone the afternoon before she went missing.

"She seemed fine and I expected to see Ciara that evening at home," he said.

Mr Glennon alerted police, who called him just over a fortnight later to say his daughter's body had been found.

He had to break the devastating news to his wife.

Australian Associated Press