Mills died surrounded by her family two days later, the Herald Sun reported on Monday.
Sister Kiani Mills told the Melbourne paper Mills was a “brighter shining star”.
“The most beautiful thing we have been able to do for the last couple of days is sit and reminisce about the incredible life that she lived and how full her life was,” she said.
“She was full of adventure and never said no to an opportunity. She would drive hours and hours just to DJ for one hour.”
Kiani Mills said her sister flew across Australia to do her job, which she “loved so passionately and to her it wasn’t a job, it was a life”.
“Being behind those decks was her sense of freedom and we got to see her light up rooms,” she said.
“I hope she is proud of what she has done because we are proud of what she has done.”
Mills’ father Andrew Mills told the Herald Sun his daughter was a “free spirit”.
“From an early age, Courtney was a bit of a free spirit,” he said.
“She took on my love of music and was her own free being.
“I’ve always loved her spirit and I always will.”
Mills is understood to have been living with her parents in Frankston after spending several years in the Indonesian island of Bali.
She attended Frankston High School and studied at the Australian Institute of Fitness, before rising to prominence in the Melbourne DJ scene.
Social media was flooded with tributes to the late model on Monday.
On a post captioned “Let’s go 2025”, one person wrote: “Lost for words, how did 15 years go by so quickly.
“You were taken away so fast. You had so much to look forward to.
“Your music will forever be in my ears. Party hard like always, sweet girl.”
Another person added: “Rest In peace beautiful girl, (you) always had all the time in the world for everyone. Rest in paradise now”.
“Rest in peace. I still remember meeting you almost two decades ago,” another person said.
Fellow DJ Brandon Mangion described Mills as a “ray of sunshine” who lit up every room.
“The last message I got from Courtney was ‘I’m here for you,” he told Nine News.
“Reading that yesterday broke my heart.”
Mills was reportedly cremated with some of her ashes to be scattered at her second home in Bali.
