A young South Australian woman killed in an alleged double murder was passionate about the environment and determined to "change the world", her family says.
Chelsea Ireland, 19, and her boyfriend Lukasz Klosowski, 19, were shot dead last month at a property near Millicent, in the state's southeast.
Lukasz' father Pawel Klosowski, 46, of Mount McIntyre, has been charged with the couple's murder.
Ms Ireland's family has remembered the mechanical engineering student as someone who left a lasting impression on everyone she met.
"Chelsea was compassionate, strong, selfless and fearless and continues to make us proud every day," her father Greg Ireland told reporters on Tuesday.
"We haven't just lost a daughter, we've lost a best friend. Our hearts will forever remain broken."
Debra Ireland said her daughter was passionate about environmental care and making changes to save the planet.
She led by example, convincing her family to recycle whenever possible, buy in bulk and reduce its use of packaging.
"She was going to change the world," Mrs Ireland said.
"She not only talked about it, she lived it."
The family said Chelsea and Lukasz were great mates and had "just bonded".
"They were an amazing couple. They were just best buddies," Mr Ireland said.
Pawel Klosowski appeared in Mt Gambier Magistrates Court last week charged with two counts of murder.
Police had been called to his property the previous Saturday night and arrested him without further incident.
Speaking to reporters at the scene, Detective Inspector Campbell Hill described the deaths as a "shocking incident to occur in the southeast".
"It's a tragic event and the impacts of this will not only be felt for the particular families involved, and the associates and the relatives, but also for the southeastern community," Inspector Hill said.