The song will be released at 8.15pm on Thursday, September 15 in New Zealand.
Last week Yelich shared a clip of herself singing the song and playing the piano on her Instagram.
It will no doubt spark comparison to her famous sister - but it comes as no surprise that the talent runs in the family.
Yelich is already a published author, having released two books: Sticky Notes in 2018 and Dudette in 2022. She first moved to Los Angeles at 17 to pursue acting before settling in New York and turning her focus to writing.
It's understood she spent some time with fellow Kiwi artist Harper Finn, who has just made the move to New York City.
Yelich spoke to the Herald in 2018 about her work and about comparing herself to her famous older sister.
"I'm probably the only one who compared myself to my sister," she said at the time.
"I have a really supportive family that have always believed in me. It was me putting pressure on myself to succeed. My own brain is my worst enemy. This book has really helped me to realise that I'm my own person with my own path."
