The blonde Hole star has had a well documented battle with drink and drugs in the past, and has been open with fighting her demons.
Reflecting on the death of Peaches, who was found dead in her Kent home on April 7, Courtney reveals how a drug-related incident between the pair led her to try and help the troubled young star.
An inquest held this month found heroin was "likely" to have been involved in Peaches' death and has been adjourned until July 23.
"[I was shocked], but then I read heroin was involved and I was not shocked. I know how Peaches liked opiates. My drug was heroin; I stopped taking it in the '90s. But I have taken pills. Peaches was in my room with a friend who had a bag full of these drugs... like 500 pills and I wanted it so badly, never have I wanted anything more -- no man, no money -- and I had to physically push Peaches and her friend out the door," Courtney revealed to Grazia magazine.
"I was shaking and I kept thinking of the way her mother died and I thought I owe it to this girl to be an example. I was trying to help her, I was trying to mentor her, but at that point in her life, it proved to be impossible. Now the parallels to her mommy are horrific. It terrifies me for my own child."
The episode left a lasting impression on Courtney, who couldn't shake the similarities between Peaches and her mother Paula Yates, who also died of a heroin overdose in 2000.
It made her question the safety of her own daughter Frances, who she had with late husband Kurt Cobain, who also fought an addiction to drugs.
Despite being born to parents who were both drug dependent, Courtney says 21-year-old Frances is a smart kid, who is well aware of the dangers her parent's vices pose.
"What happened with me and Peaches that day, when the junkie in me came out and I had to fight for the good side, brings me out in a cold sweat," she sighed.
"But the cool thing about Frances is that she knows she's related to two junkies. I mean she might smoke pot, maybe, but she's sensible. I thank God she was never introduced to prescription drugs when she was growing up."
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