Steven Williams, who confessed to the murder, was soon after sentenced to life in prison. He's since had preventive detention added on top of that for the attempted murder of inmate Nikki Roper at Auckland Prison in 2016.
Speaking to NZH Focus, near where Rex works now in central Wellington, she reflects on the day her friend was reported missing.
"I just remember coming home from school and my mum just like questioning me like did I know where she was and anything like that," she says. "I was just so young, like I didn't understand what was going on."
She fondly remembers the mischief they got up to.
"One time in class, we cut each other's hair. And we threw it in the bin and the teacher found it and gave us a telling off and then told the other kids to stay away from us," she laughed.
Attending Coral's funeral also sticks clear in her mind.
"We all got teddy bears which is super lovely because she liked teddy bears. I remember going up to her mum and giving her my teddy bear and being like 'Coral can have my teddy bear' because I don't think I fully understood the situation."
Looking back, Carline thinks Coral's death had more of an impact on her life than she realised.
"Like even now sometimes I just wonder how things would have been different.
"Because once after everything happened with her, I got moved out of that school. So all my friends that I had there, I had to make new ones," she said.
"I just jumped from school to school, so sometimes I wonder if I would have been different if she was still here."
She's grateful she later reconnected with some of her friends, who were also Coral's.
South Featherston School plans to mark the 15th anniversary of Coral's death by moving a plaque that used to be on a tree to a bench by the school entrance.
