The Victoria woman charged with abducting her daughter 18 years ago registered her child for school using government ID with assumed names that may have confused efforts to find them, CBC News has learned.

Sigourney Chisholm, seen in a 2009 photo from her high-school graduation, has not been co-operating with the police investigation into her mother, officers said. (Times Colonist)

Both Patricia O'Byrne and daughter Sigourney Teresa Chisholm — who was 20 months old when, police allege, her mother took her from Toronto amid a custody dispute with her father — were living under new names.

They had apparently valid government identification and lived public lives on Vancouver Island. O'Byrne, alias Pamela Whelan, worked for the B.C. government as a public affairs officer until May and sat on the parents committee at Victoria High School.

Chisholm was given the name Thea Whalen. She was chosen co-valedictorian when she graduated from Vic High in 2009.

School officials said they had no reason to be suspicious about Chisholm's registration because her documents appeared legitimate. Greater Victoria School District superintendent John Gaiptman showed CBC News photocopies of an Ontario birth certificate and a Canadian passport, both in the name of Thea Whalen.

"The passport, we believe, is absolutely legitimate," Gaiptman said.

'Things change'

O'Byrne, 54, and Chisholm, 20, lived in a bungalow on a tree-lined street in central Victoria. Working on a tip received in September, police came to the house Thursday morning and arrested O'Byrne on a cross-Canada warrant.

"I cannot begin to comprehend the magnitude of what this young woman has just learned," Victoria police deputy chief John Ducker said in announcing the arrest on Friday.

Patricia O'Byrne, 54, was arrested in Victoria on Wednesday in an alleged parental abduction case that stretches back to 1993. (MissingKids.ca)

Somewhat prophetically, Chisholm had written in her valedictory speech that "things change. It is flawed to make inflexible plans because nothing ever really turns out exactly the way it is supposed to.… The truth is that I am happier with who I am than who I wanted to be."

Meanwhile, Chisholm's father said Friday he’s not angry with O'Byrne, accused of abducting their daughter in May 1993.

Joe Chisholm, who lives in Toronto, has not seen Sigourney Chisholm since then.

“I certainly feel some compassion for Patricia right now,” Chisholm told CBC News.

“Hopefully she and I will get a chance to talk, bury the hatchet, whatever. They were heartfelt beliefs that she was doing the right thing. I don’t believe it was malicious. Her interest was her child. I’m not about crime and punishment. This is a family matter. I think it can be talked through.”

Never gave up search

Joe Chisholm never gave up the search for his daughter, as tips poured in over the years that she and her mother were in Britain, Spain and the United States. He began posting YouTube videos on the internet addressed to her on special occasions such as her birthday.

Chisholm also said he would like to speak to his daughter, but only when she is ready to talk.

Joe Chisholm recorded YouTube videos addressed to his missing daughter, including this one from England. (CBC)

“I can’t even pretend to imagine what she’s going through,” he said. “The reality is she’s a grown-up, she decides when that happens. I’m supportive of that. I’ve waited this long, we’ll see.”

“All of us just want her to cope with this new reality, she’s going to need some time and space to do that. None of us are looking for anything other than a peaceful resolution.”

O'Byrne's arrest followed a tip received in September 2011 through the Missing Children Society of Canada that she might be living on Vancouver Island.

Police say the Canadian Centre for Child Protection/MissingKids.ca is providing support for the alleged abductee, who lives in British Columbia.

Toronto Police Const. Tony Vella said Sigourney Chisholm has spoken to police, but officers said she is not co-operating with their investigation into her mother.

With files from CBC's Chris Brown and The Canadian Press