Karen's mum was smuggled out of WWII in a backpack. She found out years later in a letter.

Karen was four years old when she asked about the tattoo. 

She was watching her grandmother cook soup in her kitchen in Melbourne.

As she chopped the vegetables for Borscht, a popular soup in Poland, she noticed the figures tattooed on her grandmother's arm. 

"Nana, what are those green numbers?," she asked. 

Her grandmother didn't blink. 

Instead, she continued chopping and said, "That's my phone number. I had it tattooed there so I would never forget it."

Decades later, Karen now knows the truth behind those numbers and that prisoners in Auschwitz concentration camp were also branded with a similar mark during the second World War. 

But it would take her years to learn that, as it would for her to learn that the woman chopping vegetables in her kitchen wasn't actually her grandmother at all. 

***

The truth started unravelling five years later when Karen's mother, Joasia, received a letter from a stranger.

The man claimed to be Joasia's biological father - Karen's biological grandfather. 

"[In the letter] he told her that during World War Two, she had been born inside a part of Warsaw [in Poland] that the Nazis had surrounded with three meter high brick walls," Karen told Mamamia. 

The area was known as the Warsaw ghetto. 

The ghetto was home to 400,000 Jewish people who were forced to live into cramped conditions with limited access to food and supplies in the 1940s. 

Karen's mother, Joasia. Image: Supplied.

When Joasia was one month old, Nazis began rounding up thousands of people from the ghetto and sent them to concentration camps. 

"You can imagine the panic in the streets, the starving people being herded towards these cattle cars... chaos and screaming and emptying of these buildings," said Karen. 

At the time, Joasia's father knew he had to get his wife and daughter out. 

So a plan was hatched. 

In the letter he explained that one night, after the Nazis began loading Joasia's relatives on trains for the Treblinka death camp, her father crushed up sleeping pills and gave it to his daughter in an attempt to smuggle her out.

"She was given enough to kill her pretty much, so [there was a chance] she might not wake up," Karen explained. 

The one-and-a-half-month-old was then placed in a backpack, completely out of sight. 

With the help of another man in the ghetto and the use of "bribes" and "false papers", Joasia was successfully smuggled out of the ghetto on her father's back.

"My mother was nearly fainting as she read this in the letter," Karen shared.

But that wasn't all. 

Ten months after escaping the ghetto and living in hiding, Joasia's mother, Irena, was discovered by the Gestapo, the German state secret police, and murdered. 

Wither her mother dead, Joasia was adopted by her mother's sister, Alicja - the woman Karen thought was her grandmother - before they resettled in Australia.

Discovering the truth about her family in her thirties, sent Joasia in a "state of shock".

"My father heard her screaming in the kitchen [when she read the letter] and thought she cut herself with a knife," said Karen. 

Despite the shock, Joasia had long suspected she didn't belong to her parents.

"Like me, she has jet black hair and dark chocolate eyes. She used to call herself 'short, dark and wide'. And the people she thought were her parents were very tall and lanky. So she felt like they didn't look like her." 

Irena (Karen's biological grandmother and Joasia's biological mother) Image: Supplied.

After learning the truth, Joasia kept it a secret from Karen and her siblings for four years. 

It wasn't until Karen came home from school asking questions about Remembrance Day at the age of 13, that her mother told her what happened. Her grandparents weren't actually her grandparents. And her biological grandmother had been murdered. 

"I just remember screaming... and laughing and crying at the same time," she shared. 

"We were so shocked... There were lots of secrets that everybody was holding from each other. My mum held secrets from me, and there were secrets about my mother's life that were hidden from her."

Months later, Karen confessed to her grandparents that she knew who they really were. 

"We waited six months to tell them that we knew because we didn't want them to think that we didn't love them."

While Karen can't recall the conversation, she remembers later speaking to her grandmother about her past, after watching the 1993 war film Schindler's List when she was 21.

"I asked her what was the worst thing that ever happened to you during the war... And she told me she had traded little pieces of bread that they got to eat to every day [in Auschwitz] for scraps of fabric from women who came back from some of the factories."

Alicja shared she used the fabric to sew herself a nightdress that she would secretly wear every night before bed.

"There was no bathing and no showers, so she would take off her foul smelling stripped prisoners uniform and put on this nightdress on her skeletal, unwashed body. And it was a reminder that she was human.

"She said, the worst thing that happened to her was the morning that the SS found her nightdress."

Irena (Karen's biological grandmother) with her sister Alicja. Image: Supplied.

Unfortunately, Karen never got the opportunity to sit down with her biological grandmother and ask her about her past.

"My mum didn't know much about her so right from the beginning she was a bit of a ghost."

In an effort to find out more, Karen set off on an adventure through Poland to retrace her mother's steps. She's shared her discovery in her new book, Irena's Gift. 

Being able to work on the book and stitch together the mystery of her family's past has helped Karen mourn the grandmother she never knew. 

"I tried to turn her from a ghost, to a young mum who lost her little baby."

As the book hits shelves this week, the secrets that were once kept in Karen's family for generations will now be available for the world to hear. 

"A lot of the details, my family don't know so it will be interesting for them... [But] I feel privileged to be able to tell this story."

Karen and her mother, Joasia. Image: Supplied.

In writing the book, she hopes to show people the impact of the trauma of war and the importance of kindness. 

"I wanted to show people the effects of war on children and their children's children. There's plenty of people in Australia who've been through horrible wars... I just think we need to not judge people by their outward appearances."

"I wouldn't have been here today if it hadn't been for people who risked their lives to show empathy and kindness to somebody. I think that's what I really want people to take away from this story."

You can read Karen's full story in her book, Irena’s Gift, which is available here from July 18.

Feature Image: Supplied.
Cover Image: Penguin Publishing.