"Life has a way of hauling you on somehow," Mignon said.
Years ago she moved as a solo parent to New Zealand with her four children to escape the violence of her home in Pretoria, South Africa.
"I longed for safety and peace for me and my children.
"Aimee was my youngest daughter - she was a little blonde girl with a bubbly personality and who loved her homeland. She wrote about Whanganui's little 'tick tack houses' and how this was to be the start of a new life."
Mignon remembers how she and Aimee and used to dance around the kitchen floor in the house she'd bought in Whanganui.
"African music blaring, and singing at the tops of our voices, along with Johnny Clegg, Ladysmith Black Mambazo, Mango Groove and others."
Nelson Mandela was their hero, she said.
"Aimee wrote a letter to him, expressing her feelings about the injustices of apartheid. These memories were vivid in our minds, having lived through the sweeping changes that took place in South Africa after the first democratic elections.
"But how we missed our homeland," Mignon said.
"Aimee, perhaps more so than my other children, missed her father in South Africa. But we realised that we would be safer in this country."
Mignon described Aimee as a sporty girl who never showed any signs of depression.
In 2002, Mignon was teaching at Ngamatapouri School, and recalled: "One night I stood on the banks of the Waitotara River and prayed, thankful that life was looking up for us at last."
The last time she saw Aimee alive was just five days later.
"It was after Anzac Day - we were all happy and joking around the night before, with Aimee showing off her muscles from the rowing that she had been doing.
"The next day, our lives were shattered when I found that my child had taken her own life at the age of only 16 years."
Mignon swallows, her hands clasped.
"The details are too traumatic to talk about, but I can still hear myself screaming and screaming until Aimee's younger brother heard and came running. This scene will be embedded in my brain for ever."
After came the question: Why?
Mignon is quiet as she admits life was unbearably hard as they struggled to come to terms with their loss.
There was an investigation into whether the acne drug Roaccutane could have contributed to Aimee's state of mind. There was eventually an inquest, but nothing ever came of the inquiry despite extensive research into cases overseas.
Roaccutane is a prescription oral medication used to treat severe acne. While it has delivered good results for some, it's also been linked to an increased risk of depression.
Aimee was buried in Whanganui. The words on her gravestone are lyrics from a Johnny Clegg song: "Dance across the centuries, dance across the sea of time, dance and let your spirit shine, Aimee Bee."
Now there is not a weekend these days without a run or a marathon for Mignon.
Her husband Murray is supportive, extremely proud and still wonders not only how she does it, but how she does it so well - "A true pro," he said.
"I starting off walking the dogs around the bridges, then graduated to joining the Harrier Club as a walker in 2014. Then, in November 2015, I ran my first marathon in Feilding.
"Since then, I have run 15 marathons and about the same number of half marathons and other events like the Tussock Challenge and the Goat Tongariro."
As a member of the Wanganui Harrier Club, Mignon has had top three placings in her age group, and was first in her age group as a registered runner in the 2015 Auckland Marathon.
"Always being an academic who never played sport, these successes have come as a surprise to me," she said, adding that running had changed her life.
"It makes me feel powerful and normal again. Marathon running has pushed my body beyond what I ever thought I was capable of achieving.
"I wear a yellow ribbon for every marathon event and, as I run, I hear Aimee saying: 'Come on, Mommy - you can do it'.
"If Nelson Mandela can survive 27 years in prison, surely I can cope with this? I am - in Madiba's words - "Free, at last."
Mignon now teaches at Whanganui High School.
"I like to think that my running has inspired my students to achieve."
At the end of the month she will run the Auckland Marathon, striving to attain a new personal best, wearing a special yellow T-shirt with a picture of Aimee.
"It's about filling my life with positive things and surrounding myself with positive people."
Next month Mignon will line up in the three-day North Island Masters event in Palmerston North. She has entered the 5000 metres, the 1500m and the 1300m.
"I heard of a woman who was still running at 95 - I really want that to be me one day."