Katerina Koneva's family had come to Britain to escape the war-torn area of Macedonia.
Zaklina Konev visits her daughter's grave nearly daily
Their new life in Hammersmith, west London, had flourished for two years.
Her father Trajce was a mature student learning English at the local college and Katerina, a bright, quiet girl, spoke good English and attended Holland Park School.
But their new-found happiness evaporated in May, 1997 when Katerina returned from school to find convicted paedophile Andrezej Kunowski waiting for her.
The illegal immigrant tied a piece of cord tightly round her neck and slowly throttled her.
He was disturbed by Katerina's father and jumped out of the window, leaving Katerina for dead.
Katerina was killed in her own home
Katerina's mother, Zaklina, visits her daughter's grave almost every day.
At home, a shrine commemorates the life of the 12-year-old who was murdered by a paedophile who should never have been freed.
Zaklina and Trajce are now divorced. Zaklina is living in a new flat in Hammersmith with her son Christian, 12.
Mrs Koneva has bought Katerina Christmas and birthday presents every year since her daughter was murdered.
She said: "I talk to her every day. We say goodnight to our children, don't we? So I always say goodnight to my daughter."
In an angry statement after the verdict, she said: "Today I do not feel happy. I wish that I was not giving this statement and that Katerina was still here by my side.
"I am relieved that this evil man is no longer free to murder or sexually assault another young girl.
"Today I do not feel that justice has been done. I hope that this evil murderer burns in hell.
"Knowing he is in prison is not enough for me. I hope he suffers every minute of the rest of his life.
"All life imprisonment means is that other children will be safe and no other parent will have to go through what we have because of him."
She also feels bitter that the serial sex attacker who took Katerina's life fled to Britain from Poland where he was under arrest for rape.
A Polish judge gave him three months bail to get a hip operation.
Left unsupervised, he did not have the operation but came to Britain, entering as a tourist, and then becoming an illegal immigrant.
Kunowski was a convicted paedophile
Mrs Koneva said: "I am aware that he had serious criminal convictions and impending prosecutions in Poland.
"Something must be done to ensure that such a thing does not happen again."
She also felt police would never catch her daughter's killer.
Two months after Katerina's killing, Princess Diana died in Paris. Public interest switched away from the murder of a schoolgirl in London.
Two years later the senior officer in the case, Detective Superintendent Hamish Campbell, was switched to the Jill Dando murder inquiry.
"That was when I felt the investigation was over. I felt very angry."
For Mrs Koneva it is the end of a long vigil.
She attended court each day of Kunowski's trial and collapsed outside court after hearing the pathologist's evidence.