Mrs West, 41, who denies murdering 10 girls and young women whose remains were found at two houses, where she and her husband lived in Gloucester, gave evidence at Winchester Crown Court.
She said she was born in Devon but that the family later moved to Bishop's Cleeve, near Cheltenham, Gloucestershire, where she grew up as one of seven children in the Letts family.
Mrs West told the court that when she was 15 she was the victim of two rapes. The first was when a stranger gave her a lift home from a Christmas party, which she accepted reluctantly.
She said that the man drove past her home to some hills where he raped her and added: "I honestly thought he was going to kill me."
Asked by Richard Ferguson QC, defending, if she had told her parents about this, she sobbed as she replied: "No I didn't."
The second rape took place when a man approached her as she was waiting for a bus. He started talking to her and when she became frightened and ran away he dragged her into a park and raped her. Mrs West cried as she told the court about the attack.
She also described the break-up of her family, when she went with her mother and younger brothers to live at the home of her married sister, Glenys, in Cheltenham.
"I had a job by this time and I came back to my sister's after work, and my mum and my brothers were not there. I asked my sister where they were. They were gone, they had moved on.
"It had a devastating effect on me at that time. I had left my father's home and I expected the support of my mother, and she just left me, she abandoned me."
As a result of the second attack she started using the main bus station in Cheltenham and it was there that she met Mr West, who also lived in Bishop's Cleeve. Her initial reaction to him was "shock and horror" but he persistently asked her out and she agreed to go to the village pub with him.
She said: "He had promised me the world, promised me everything and because I was so young I fell for his lies but because I was so young I did not realise they were lies at the time. He promised to love me and care for me and I fell for it."
The Wests married and moved to 25 Cromwell Street, Gloucester, where Mr West suggested that they take in lodgers. She said that Mr. West persuaded her to have sex with some of the lodgers. She told the jury: "He was always on about other men. He would use emotional blackmail, he could be very very persuasive."
But she added: "It was almost as though he was jealous of the other men that he was forcing me to go with. If he thought he was losing an argument he would use his fists and hit me. It was a regular thing."
As they led increasingly separate lives, she began to have lesbian relationships. "My sexual relationships with other women were very special to me. They were entirely different to when I went with a man. They were warm, close and I would say they were more fun."
Mrs West told the court that she had tried to stop the sexual assault on Caroline Owens in 1972. Mrs West said: "I remember Fred saying to me about getting involved with Caroline Owens in a lesbian relationship which would have been my first experience with a woman. He did persuade me that Caroline Owens was willing to try it out.
"As soon as she put up resistance, as soon as I realised that she was against this, that she did not agree with it in any way I stopped." She said that she could not remember them taking Mrs Owens back to their home, adding: "I have tried very hard to remember these events but I just can't. I was a young girl, I had been conned into this situation.
"It was terrifying, I believe that I was as much a victim as Caroline was," said Mrs West, who added that she had been intimidated and that she had never broken the law before.
"I didn't want my children taken away, I was terrified that I would lose my family," said Mrs West, adding that she had wanted to leave her husband but had nowhere to go.
Earlier, Mr Ferguson, opening the defence case, said Mrs West "neither knew nor took part in any of the activities which led to the deaths of these girls nor did she knowingly do anything afterwards either to hide or conceal these murders".
Mr Ferguson said that the jury might think that it was "as plain as a pikestaff" that Mr West had been involved in the murders. "If it is a fair assumption that Fred West murdered before he even met this defendant then some consequences become immediately apparent.
"It is apparent, is it not, that he was capable of murder without her assistance. It is also apparent that he was capable of dismembering and disposing of the bodies without her knowledge, help and assistance."
The trial continues today.