Lisa Ann Rush died on Monday four months after her daughter Amber-Rose Rush was found dead in her Corstorphine home on February 2.
Dunedin doctor Venod Skantha is accused of murdering Amber-Rose.
A police spokeswoman this afternoon confirmed a woman in her 40s was found dead at a Dunedin property late on Monday night.
The death was not suspicious and would be referred to the coroner, the spokeswoman said.
Lisa Ann's son Jayden Rush posted on social media this morning saying their mother had "departed the realm of the living to continue her journey along side Amber Rose and to forever watch down over us in peace".
"Although we are all so devastated to see such an important part of our life gone, and it makes our sorrow that much deeper, we are all so glad that her suffering is now over and she can rest easy for all of eternity..
"Love you mum, you were all I focused my life on for the past 4 months. Don't know what I'm gonna do now without ya but I'll find a way.. fly high and kick Amber's ass for me," he said.
She died on Monday, he said.
Amber-Rose's sister Shantelle Rush confirmed the death to the Otago Daily Times and said her response to the news was of "total heartbreak".
"I'm lost for words at the moment," she said.
In comments on Facebook, which she gave permission for the ODT to use, she told her brother "we haven't got much left but we will always have each other".
"I don't even have words for the amount of heartbreak I am feeling right now. I honestly thought we couldn't go through any more pain than we already were but I was wrong.
"Unfortunately last night Mum went to be with Amber Rose. We are absolutely devastated and don't know how to get past this.
"Our family will be forever broken... but mum, I hope you are at peace now with Amber.
"And I hope you never ever forget the amount of love me, Jayden Rush, Ollie, piper and the rest of our family all have for you.
"See you on the other side."
The teen was found dead in her Corstorphine home on February 2 and Skantha was charged days later.
Amber-Rose's mother Lisa Ann told the Otago Daily Times last month that the release of Skantha's name was no consolation for her.
''Nothing makes this any better.
''I can't deal with this on top of the loss of my child. I don't think anyone understands,'' she said.
''We have to sit there quiet and not say anything.
''All I want to do is stand up and say how amazing she is,'' she said.
In the days following Amber-Rose's death, police launched a search of waterways at Blackhead.
They later confirmed they had found ''an item of interest''.
They then asked for public sightings of a silver BMW travelling between Dunedin and Balclutha early on February 3.
Skantha is scheduled to appear in court again in July.
His trial is set down for March next year.
Where to get help
Healthline: 0800 611 116
Lifeline Aotearoa: 0800 543 354
Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO)
Samaritans: 0800 726 666
Alcohol Drug Helpline: 0800 787 797
General mental health inquiries: 0800 443 366
The Depression Helpline: 0800 111 757
Homecare Medical: 24-hour 1737 free text/phone
Youthline: 0800 376 633, txt 234 or talk@youthline.co.nz
What's Up (for 5-18 year olds; 1pm-11pm): 0800 942 8787
Kidsline (aimed at children up to age 14; 4pm-6pm weekdays): 0800 54 37 54 (0800 kidsline)
