'I wanted to write about Vicky.'

For 17 years Sharon Brown has dutifully kept stacks of pocket diaries, newspaper clippings, court papers and family photographs that record the search for her sister Vicky Hamilton.

For 17 years Sharon Brown has dutifully kept stacks of pocket diaries, newspaper clippings, court papers and family photographs that record the search for her sister Vicky Hamilton.

They capture the thoughts and feelings of a family torn between sadness and the hope that one day answers would be in place to explain why 15-year-old Vicky vanished without trace in 1991.

Most of the documents are bagged up behind the ironing pile in the kitchen of her home in Falkirk, but now Ms Brown, 37, hopes they can be packed away more permanently.

"Hopefully I am finished with these now. I will pack them away in a suitcase and put them somewhere. Not forgotten, just packed away."

Ms Brown appears calmer and less pained than she has been in the past as she flicks through the papers and pictures that chart not just Vicky's disappearance but the years of her own life that were taken over by the case.

She was only 17 when Vicky went missing less than an hour after the sisters has said goodbye outside her flat in Livingston.

The two had spent a brilliant weekend together, going to the pub, dancing, drinking and shopping.

It was only last month, when Peter Tobin was sentenced to 30 years for the rape and murder of the teenager, that she could start to make some sort of sense of what had happened to her little sister, who never made it back to her mother's home.

The family archive can also be put away with a sense of closure as Ms Brown has finished writing a book on the experience of losing Vicky and the darkness that it cast over her life.

She said there were "a thousand" reasons why she wanted to write the book - Taken: The Agonising True Story of My Missing Sister - adding that it helped her to organise her emotions at her lowest points.

"I have been writing notes since Peter Tobin first came to my attention and when they found Vicky's body. It was the night of Vicky's funeral that I decided I was definitely going to do the book. I found my hand couldn't keep up with what I was thinking.

"It was self-healing; it helped me come to terms with a lot of things. It was also incredibly difficult to do in parts, like writing about my mum's death.

"Going back in time like that and remembering the feelings I had then was not easy.

"I would think of my mind and think of grey smoke with loads of words running around. As soon as I put pen to paper I could barely keep up with all the thoughts. To have my head emptied like that brought me so much relief."

The book is being marketed in the style of a "misery memoir", one of the most profitable publishing genres of recent time, and will be released on Thursday. It reveals intimate details of a family whose feuding came into public view following the discovery of Vicky's body in November 2007, when Ms Brown and her father Michael Hamilton were divided over where to finally lay Vicky to rest.

The publication describes the schoolgirl's young life and disappearance along with details of a marital affair, a marriage break-up and the hardships of life in a single-parent family.

Ms Brown writes of the effects of losing her mother Janette in 1993 and then bringing up her younger twin brother and sister, who were just six when Vicky went missing.

Ms Brown, who has a 12-year-old daughter and a three-year-old son, says she wanted to put across her own version of events in response to media interpretation of her family's difficult relationship.

"It was quite important for me to get that all across but at the end of the day the book is about Vicky, the book is not about my dad and it is not about me. I wanted to write about Vicky, about the person. She was more than just an image in a school photograph.

"You don't expect evil to touch your family but Tobin single-handedly destroyed my family.

"He took my mother and he took my sister. You would think that this would bring what was left of my family closer, but it didn't. It just made the divide more serrated."

She says she was slightly apprehensive about baring all in the book, but adds that it was on a trip to the garden where Vicky's remains were found that she decided she was doing the right thing.

"I travelled down there last June and went to the garden. When I finally got through the gate, the whole area was covered with poppies, a remembrance. The whole ground had been churned up and the poppies had just grown there. When I saw the book cover the publishers had designed, it had a little poppy on the back. I knew then it was right."