The woman said a car matching the same description as Robertson's had been seen in the same area the day before the attempted abduction.
The morning after the 5-year-old girl was abducted she told Maungatapu School's principal about Robertson's approach to her son and niece, and that information was passed onto police.
"It was only about half an hour later the little girl was kidnapped and under an hour later she was found by the detective. I was told later this information was instrumental in him finding her."
The woman said her son and niece gave a video-taped interview about what happened and despite Robertson's denials, the evidence against him was overwhelming.
"I have never really talked about it before with anyone as I tried to put it behind us, but talking about it has brought it all back again. It was a very anxious and disturbing time for me and everyone involved," she said.
The woman said she now is in a relationship and has gone on to have three more children, including two daughters, aged 3 and 6.
"I can only imagine what it must have been like for the little girl and her mother as I'm very protective of my children particularly my two little girls. I really felt for the family of the living girl... It's a parent's worst nightmare."
"I thank God that day he protected my little boy and my niece. It's frightening to think what could have happened to them if Robertson had managed to get them into his car," she said.
The woman that said back in 2005 she was a solo parent and worked.
"I always felt guilty my son had to walk home from school without me being there, and soon after I put him into after-school care," she said.
Over the years she was sent papers inviting her to make victim submissions whenever Robertson's parole hearings came up, but chose not to, nor did she attend his trial because she did not want to see him or give him any more of her time.
"I never really felt like a victim as nothing actually happened to my son and niece. The little girl was the real victim because she was abused by him and I'm sure she was left emotionally and psychologically scarred from what happened," she said.
The mother said her eldest son is now aged 17 and her niece is 16 and they have grown up to be "beautiful, loving kids" and she would not want to see them have to relive what happened to them.
The mother of the 5-year-old girl told the newspaper she did not want to talk about what happened all those years ago, other to say "He [Robertson] deserves a bullet".