The freezing cold snow around her shoeless feet is Lady Zahava Kohn’s enduring memory of Bergen-Belsen concentration camp.

Last Tuesday marked 70 years since Lady Kohn was freed from the Nazi camp in Germany aged nine. She had suffered two years of starvation, illness and humiliation.

Most days, the 79-year-old tries not to think about her time in the camp, the name of which has become synonymous with the horrors of the Nazi regime.

But following decades of staying silent about her painful past, Lady Kohn, of West Heath Road, Hampstead, now feels able to travel across the UK with her daughter Hephzibah Rudofsky to talk to schoolchildren about her survivors’ experience.

Last Tuesday, mother and daughter gathered together a small selection of friends and community figures at Ms Rudoksky’s West Hampstead home to keep the memories alive once again: the theme for this year’s Holocaust Memorial Day today.

“People should know what happened, and people don’t really understand what all these people had to go through, because they can’t believe it,” Lady Kohn said.

“The anniversary does make some kind of impression.

“I have one particular picture in my mind of us gong onto the train [out of the camp] and I remember being with my parents going through the border.

“I was so weak and my parents had said to the camp leader that I was too weak to move.

“It was an unbelievable thing to have to go through that.”

Lady Kohn was born in Palestine in 1935 to Polish parents but two years later, the family settled in Amsterdam.

Sixteen months after her brother Jehudi was born, her mother and father made the heartbreaking decision to leave their baby son with the Dutch Resistance rather than risk him being taken to a Nazi labour camp.

They hoped his “Aryan” blonde hair and blue eyes would keep him safe from the wide-scale round-ups of Dutch Jews.

Indeed, when SS guards arrived at the orphanage where he was living, he was one of only two children spared from deportation to the camps.

“I wasn’t allowed to talk about my brother,” Lady Kohn remembered. “As a young child, I was told not to mention anything about him because I might give something away. To tell a child of seven-and-a-half that you must forget your sibling, I was too young to understand.”

Six months after Jehudi was sent away, the SS arrived for the family and took Lady Kohn and her parents to a transit camp.

Nine months later, they entered Bergen-Belsen, where her mother and she were separated from their father. Her mother looked after the officers, a job which allowed her to collect cigarette butts and swap them for crusts of bread.

Their only meals were crusts for breakfast and thin turnip “soup” for dinner, with no food in between.

Lady Kohn spent most of her years there ill and too weak to even move from her bunk.

Her mother kept her as protected as possible from the death and despair all around them, something which Lady Kohn is deeply grateful for.

“I’m just surprised that I could go through with it,” she said. “My life was just lying on the bunks waiting for my mother to come back.”

When she could get up, she would be made to stand outside in all weathers for daily roll-calls.

“I remember very clearly that we had to be counted every day,” Lady Kohn said.

“We had to stand still and quietly, more or less in bare feet because we had no proper shoes.

“They would keep us there for hours. They just kept saying that someone was missing, but that was their way of keeping us down. There was nothing we could do.”

Bergen-Belsen was initially an exchange camp where Jewish prisoners were freed in return for German prisoners of war held by allied troops.

This was eventually how the family was freed on January 20, 1945, three months before the entire camp was liberated by allied forces on April 15.

Close to death, Lady Kohn weighed just 23kg (3st 8lbs) on leaving the camp.

She said: “I was so weak. I wouldn’t have had a chance to go on much longer. I was absolutely starved and gravely ill.”

The family was reunited with Jehudi in 1946, and began to lead a normal life once again.

Their time in the camp was never mentioned by her parents again, and for decades Lady Kohn stayed silent about her experiences even from her children.

It was only when her mother died in 2001 that a suitcase full of chilling keepsakes from the war years was discovered and Ms Rudofsky persuaded her mother to remember once again.

Her memoir, Fragments of a Lost Childhood, followed and in 2009, the pair launched Surviving the Holocaust, a programme in which Lady Kohn speaks to pupils at schools in London and across the country about her experiences.

Ms Rudofsky, 51, who works in Holocaust education, said: “I ask myself every day, how did anyone survive the camps?

“Sometimes I have to distance myself because it’s too painful to hear what she actually went through, the suffering, the pain and people dying all around her.”

The mother-of-two, of Ranulf Road, added: “Some children have never met a Jewish person before, so they may have been biased perhaps in what they have heard.

“But then they see a normal person telling an abnormal story covering something in a matter-of-fact way so they can really relate to that part of the past that happened so long ago now.”

Lady Kohn has now spoken to thousands of schoolchildren at dozens of schools, but the memories never lose their power over her.

“There are certain days when I have more feelings about what was happening,” she said. “I have to prepare myself.”