Robyn became one of the Capital's youngest homeless children at just 12 after running away from the Muirhouse home that she shared with the drug-addled mother she could no longer look after.
Now 16, Robyn, who has kept her surname anonymous, described for the first time the squalid living conditions she encountered living on the streets of Edinburgh.
Finding shelter in graveyards ridden with needles and violent drug addicts, she struggled to survive on bars of chocolate and exchanged the gold crucifix her mother had given an older homeless man. At one point Robyn found herself injecting heroin seven times per day, dropping from nine to six stones in weight.
She said: "I just came from an environment where bad s*** was happening all the time. Looking back it was probably the fact that I was desensitised by everything at that age.
"All my money was just going right up my arm. There was nothing that could happen and nowhere I could go and nothing that would shock me because I pretty much expected to die anyway."
Robyn, one of six homeless teenagers followed by a Dispatches film crew over six months for last night's C4 documentary Britain's Street Kids, said her life went off the rails after first being given heroin at a drug-fuelled party at her home.
She said: "I grew up on the rough Muirhouse estate, where drugs were practically sold on every stair. The first time I had a hit I was in my bedroom with the door shut trying to stay out of the way while my ma and her pals were partying.
"There were a lot of low lives around. One guy came in asking if I'd like to try some heroin. He told me to give him my arm, which I did. Although I knew it was dangerous, nothing inside my head said 'No'.
"I remember feeling good but fearful as I drifted off. From then on I took heroin on odd occasions when my ma was sleeping. It was like a door had been opened."
Asked how she would describe her family life, she said: "I would probably describe it as extreme in the sense that when it was good, it was fine and it was great, but when it was bad, it was horrifying.
"I used to go to bed at night with a knife under my pillow.
"Everything deteriorated. My ma deteriorated. I deteriorated. I was taking drugs. The school knew I was taking drugs and I was going to school wasted."
Robyn was taken into care but ran away a few days later, as do 30 per cent of children bought up in social care.
"I had 30 to 40 police charges against me in two weeks," she said. "I was made up of violence, anger and drugs. That's what I was taught and that's what I still believe in."
Robyn soon found herself living in the Capital's cemeteries after running away from home aged 12. During the film she took the crew through an unnamed city graveyard, strewn with needles and human waste.
"If you're on the streets of Edinburgh this is where you're going to end up," she says.
During the documentary, Robyn was shown preparing heroin and injecting it, before sinking back from the effects.
Despite having seven support workers from various agencies, Robyn said she regularly encountered shocking violence on the streets of Edinburgh.
"I've met people (on the street] who are animals," she said. "Rapists, paedophiles and the mentally ill, who are ill to the stage when they would chop you up because they were in a bad mood. I would say there's two groups of people on the street: you've got the predators and you've got the prey.
"I think I am a good person but it's deep, deep down in me. It's like dirt and I've tried to get it out every single way."
Robyn is now clean from heroin and thanks to regular meals at her long-term hostel, 50 a week in benefits, counselling and a small income from selling the Big Issue magazine, she hopes to one day work with children.
Speaking about the documentary, Robyn added: "I took part to show other young people how awful it is being homeless. I want them to see how I messed up my life."