Sandie Jessamine was just 12 years old when her life started spiralling out of control.

Sexually assaulted, disowned by her family and sent to institutions for 'delinquent' girls, she has now opened up about her harrowing ordeals - including how she had to live with a teen killer.

Sandie was packed off to Reiby Training School in Sydney in 1974 after her behaviour went downhill following an attempted rape by her friend's brother when she was 12.

Sandie was mucking around with 'Lisa' in her bedroom when her older brother, 'Mark', barged in.

'He was fifteen and usually ignored us. Why did he want to hang out with eleven and twelve-year-olds?' Sandie writes in her book Borderline.

Mark told the girls he had 'something special' to show them. He took them to a nearby paddock where an enormous tank was lying on its side.

They crawled inside, and he dared the girls to strip. They both did out of terror.

Mark then tried to rape Sandie, but she managed to get away from him.

Life became even more of a nightmare for the young girl in the town of Windsor, New South Wales, after Mark told everyone at school that she had willingly slept with him.

'At the train station and at school those boys pinned me to walls. I'd kick their shins as they'd lift my uniform and put their fingers in my pants,' Sandie said.

'They'd stand in a circle so no one could see. Kids did. They said nothing. It didn't happen every day but every day I was scared it would.'

Sandie, who was adopted, started wagging school and then ran away with another friend. She received the 'thrashing of her life' when police took her back home.

Tearfully she told her parents that she wasn't going back to school.

Her father told Sandie she was an 'embarrassment' and her trouble started 'because she let that boy in her pants'.

The traumatised girl, who was starting to display signs of mental illness, was sent to live with her grandparents in Gippsland.

She stayed there for a while but became bored and returned to her family who had since moved to Wagga Wagga.

It turned out to be a big mistake.

She made a new friend called Christine.

'Within weeks we were wagging school,' Sandie said.

'I began shoplifting like I'd done when I was small. Got caught with a baseball cap. Wound up on probation.'

She then ran away with Christine.

'When it got dark we found a railway shed in a little town. It was nearly winter. Freezing. We cuddled under a tarp. I'm sure rats ran over me.

'In the morning we noticed a tin trunk with old cheques inside. We stole them because we were hungry and because we could.

'When we tried to cash them, the bank called the cops, who charged us with theft and kept us in a cell until our parents arrived to be in court with us.'

Sandie, who already had a record for stealing, was committed to an institution for six months.

She was first sent to Minda Remand Shelter in Lidcombe, western Sydney, when she had to undergo a painful gynaecological examination to check that she wasn't 'diseased' or pregnant.

Then she was taken to Ormond in Thornleigh where she was thrown into an isolation cell after she tried to escape to see her grandfather who had suffered a heart attack.

Finally she was transferred to Reiby Training School in the Sydney suburb of Campbelltown and moved to Robinson, a cottage 'for tougher and older girls'.

Psychological reports at the time stated that Sandie was 'an intelligent and mature girl with a great deal of insight into her situation'.

But superintendents and psychiatrists saw her differently.

'Sandra has been seen at length by the senior psychiatrist … He sees little possibility of successful treatment.

'Essentially, Sandra has a character defect that is not responding to psychiatric treatment … He has prescribed a Mellaril dose which Sandra takes very willingly and this has undoubtedly helped her remain settled in recent weeks.

'I would not be prepared to give a favourable prognosis for her future,' a superintendent at Reiby said in 1974.

Another said: 'There is little doubt Sandra is a cunning and devious girl … she has been trying to improve her performance to … earn discharge. She has been given no help of any kind and has had to earn every point … Discharge is recommended.'

Sandie was released from Reiby in March, 1974, the day after her 15th birthday.

'My parents couldn't pick me up, so an escort took me to Wagga. She shook me awake as the train neared the station.'

Sandie found it hard to adjust to life at home. She refused to go back to school and took a secretarial course before finding a job packing shelves at the local Woolworths.

She met a man, Steve, a 20-year-old army recruit. He took her on a date where they ate hamburgers in the local park before he asked her to go with him to a hotel room where his mates were.

'His three friends were sitting on a bed, watching TV. They made room for us and handed me a bottle. The drink tasted funny, like aniseed,' Sandie said.

'My new boyfriend kissed me and said I had nice eyes.'

Steve started having sex with her while his friends stripped and waited for their go. However Steve 'jumped off' Sandie when he realised she was a virgin.

He told his mates that Sandie was 'jail bait', and that if they 'all went through her and she screamed 'rape' they'd be done for'.

Steve dropped her home and warned her not to say anything. Sandie went inside and took an overdose. She was rushed to hospital and survived.

'I didn't want to leave the bedroom after that,' she said.

She attempted suicide again. Her mother told Sandie her life 'wasn't that bad', while her father threatened to return her to 'that girl's home if she didn't snap out of it'.

After she started a fire in her bedroom a welfare officer came to the house and she was taken to court.

A district officer at the time said: 'The family are still very anti-Sandra because of her quick temper and lack of inner control and there appears to be a sigh of relief over the whole house since she left.'

A magistrate in the New South Wales Children's Court charged Sandie with 'being uncontrollable' and she was sent back to Reiby before she was taken to the Kamballa Special Unit in Parramatta, where there were only two other girls.

'Kamballa was an experiment to see if unmanageable girls could be rehabilitated if staff taught life skills and fostered relationships with us,' Sandie said.

'It was a response to feminist protests about brutal conditions at Parramatta Girls Home, yet out of hundreds of girls in custody, only a dozen arrived at Kamballa while I was there.

'We were deemed the wildest, the saddest, a bit different from the rest, the so-called wickedest or peculiar, and while I was there no one could reach in and save me.'

At Kamballa, Sandie was forced to share a room with 'Kelly', who had been convicted of murdering a person in their sleep.

Sandie was terrified on the first night she shared a dormitory with Kelly.

'I noticed her eyes were sad. Did it show in my face that I saw her as a killer?' Sandie said.

'We were dwarfs in this huge dorm. I wondered how silence could sound like an echo and wished the ceiling was lower so I would feel tucked in.'

Kelly told her to pull her bed closer 'so they could whisper'.

'I waited for her to share her secrets. Instead she talked... about how her parents brought parcels in every Sunday. Stuff other chicks would say,' Sandie said.

'For the first time in ages I missed home. I didn't want to think about my family but couldn't help it.'

Sandie and Kelly soon became friends.

'It was funny how a chick could go from being a killer to a real cool mate. We'd make up dance steps. We wanted leather jeans like Suzi Quatro,' Sandie said.

Kelly only talked about the murder once - on the anniversary of the crime.

Sandie said that Kelly described the day she had done it as a 'monster living in her body'.

'She said that people thought she didn't care about the victim, but she did. And that she feared 'there were two' of her.'

Sandie, Kelly and a few other girls hit headline news when they escaped from Kamballa by jumping over a wall.

They broke into a house and stole $5 before heading to Kings Cross where they found an old friend who was working as a prostitute.

Kelly decided to go and visit her parents in a nearby suburb. Her father told her that she had 'five minutes to explain herself' before he called the police.

Sandie and another girl were soon captured and thrown into a police cell where Sandie was bashed by a police officer. They were sent back to Kamballa.

Sandie was blamed when Kelly was caught and sent to an adult prison, as the other Kamballa girls assumed Sandie had lagged to the cops.

Sandie decided to escape again with a girl called 'Farrow'. They ended up in Redfern and lived with other homeless teenagers.

'Without it having occurred to me to do it – and I meant ever, even though I'd absconded before and run off from home – I became a street kid, roaming with my gang,' Sandie said.

'The rules from my 'family' were no help on these streets. Don't talk with food in your mouth. Be polite to adults and never interrupt if someone's speaking.'

Sandie's world came crashing down again when she was violently raped. She was later picked up by police while she was sitting in a gutter.

'I'd been bashed. I'd been hated. I'd been raped. I had to wake up. I screamed and ran, ran and screamed, and sometimes later as I sat in a gutter, a cop car pulled up, ' Sandie said.

She asked the police officer if he was going to bash her.

'My shoulders slumped. I was too buggered to care,' Sandie said.

She was taken to a holding cell.

'Two days later I stood in Minda Children's Court, staring at the floor, knowing I faced at least another four months behind bars,' she said.

However the Magistrate decided to give her a chance after saying that he 'saw something in her, and believed she could make something of her life'.

She was returned to Kamballa with no extra time added.

'I was unsure I'd heard right. What just happened? I mouthed thank you then broke down and cried. I could do it. I could behave. And then it would all be over,' Sandie said.

'I had to let the rape go. Who'd be on my side anyway? Look what had happened when I blabbed about those Windsor boys, and that was my family turning against me.'

She was released on July 1, 1975, after two years behind bars. She went to live with an Aboriginal woman who had visited Sandie in the institutions and had encouraged her to survive.

Sandie went on to complete a Master of Education and eventually became a teacher in New South Wales prisons where she taught creative writing.

But in her mid-fifties she had a mental breakdown inside a jail where she taught former corrupt police officers who had been sentenced for crimes.

She was diagnosed with Borderline Personality Disorder, Complex Post-traumatic Stress Disorder and severe Dissociation.

Sandie had also worked as a health educator and an alcohol and other drugs counsellor but her career was at an end.

In 2105 she returned to Kamballa to reclaim the lost girls within her that she had left behind in the institution. She said it was time to nurture and bring those parts of herself home.

Borderline by Sandie Jessamine is out now by Bad Apple Press.