Shaun and Josie Russell moved to Gwynedd's Nantlle Valley from Kent after Josie's mother and sister were killed in an attack which left the nine-year-old with severe injuries.
Josie Russell passed eight GCSEs last year
The Russells sought to rebuild their lives in north Wales against the backdrop of two murder trials and Michael Stone's eventual unsuccessful appeal against his conviction.
The failure of Stone's appeal on Wednesday means he will continue to serve three life sentences for the hammer attacks.
The Court of Appeal verdict comes a week ahead of Josie's 18th birthday.
Her father said: "Josie and I have made an effort to put our memories of this terrible affair behind us".
Following Stone's attack on Lin, Megan and Josie Russell in a country lane in Chillenden, Kent on 9 July, 1996, all three were believed to be dead when found by police.
It was only when a policeman at the scene noticed Josie move that it was realised she survived the attack.
Despite severe head injuries that affected her speech, Josie went back to school in 1997 and was later able to help police with details of the murder.
Within weeks of the murders, Shaun Russell left the job he had taken up as a scientist and conservationist at the University of Kent and returned to the quiet north Wales village of Nantlle, which had once been the family home.
As the seven-year legal process that saw Stone convicted twice and his appeal rejected went on, Josie and her father returned to normality in the largely Welsh-speaking community of some 100 people.
Speaking in 1998, Shaun Russell told of the difficulties his daughter had faced since the attack.
He said: "The main victims were my wife and Megan, they died.
"But Josie is a victim who has had to suffer then and now and further into the future."
But Josie improved with time and last year she passed eight GCSEs. She is now continuing her education at Coleg Menai.
Her former headteacher, Dewi Jones, said she had achieved a tremendous amount.
He added: "If we thought of Josie and put her in the context of success in GCSE examinations at the end of year 11 in school, I don't think anyone would have dreamed that she would have succeeded so well.
"That's been part of her total development, not just academically but socially and personally."
Nantlle community councillor Les Jones said Shaun and Josie Russell had settled well since returning to north Wales.
Lin (left) and Megan Russell were killed in the 1996 attack
He added: "They've more or less blended into village life. I think they've gone through more than ordinary people have to go through.
"Let's hope this will be the end of the saga because I think they deserve a bit of peace and quiet at long last."
In a statement released after Stone's conviction was upheld by appeal court judges in London, Shaun Russell said he hoped he and his daughter could now be allowed to get on with their lives.
Mr Russell said: "Josie and I have made an effort to put our memories of this terrible affair behind us, especially as nothing can bring back Josie's mother Lin and sister Megan.
"We would be grateful if we could be left in peace with our happy memories of the ones we have lost, and to get on with our lives in as private and undisturbed a way as possible."