Chelsea Ireland and her boyfriend Lukasz Klosowski were just 19 years old when they were shot dead by Klowoski's own father at his property in South Australia's south-east in August 2020.
Now, their parents are promising to do what they can to fulfil their unfinished dreams.
"They had dreams. They had their life planned out... and it was just cut short," Chelsea's father Greg Ireland told 9News.
He and Klosowski's mother, Magda Pearce, are preparing to travel to the United States in November to run the New York marathon - a gruelling 42.5km race through the city's streets.
"I came across a bucket list that Chelsea had written up in primary school," her dad said.
"Two of the things on the bucket list were to travel to the US and to run a marathon.
"(She) couldn't have picked something easy!" he laughed.
Lukasz' father Pawel Klosowski was sentenced to life in prison with a non-parole period of 34 years in April 2021 after he pleaded guilty to shooting the teens at his Mount McIntyre property.
It's something that Lukasz's mother has never spoken of in this way before.
"The way they died was completely, not even remotely related to how they lived their lives. Their lives were nothing like that," she said.
Ireland said running the marathon was about "the love we have for our kids, and to be able to achieve something that they dreamed of and never got the chance".
In the lead-up to the race, the grieving parents are raising money for the Breakthrough Mental Health Research Foundation in memory of their children.
"This is going to be so emotionally challenging - physically challenging for sure," Pearce said.
"We're going to be carrying our children on our shoulders."
