Mrs Janssen was born Olga Revermann, in Utrecht, in the Netherlands.
She studied home economics and applied sciences and was able to work making clothes.
By 1942, she moved to Nijmegen and began delivering resistance newspapers criticising the Nazi regime to several cities.
"We organised food or stole food to give to people who needed it. People who were hiding, we looked after them. You steal from one and give to the other."
In late 1944, she was stopped by a police officer whose wife suspected her of holding resistance literature.
The officer looked inside her bag, found the papers, and arrested her on the spot.
She was taken to several political prisons including Ravensbruck concentration camp in northern Germany before being eventually transferred to Dachau, the first Nazi concentration camp, northwest of Munich.
Every day she would walk 2km, sometimes through snow, to a factory to darn socks.
At one point she became ill and had to have her gallbladder removed at the camp.
Liberation did not come until June 1945, when she was part of the last group evacuated by United States forces.
In the late 1940s, she met Caspar Janssen and the two had a "wedding celebration" on May 31, 1952.
Seeking a fresh start, the couple moved to Dunedin the next month and officially married at St Joseph's Cathedral on August 1.
They lived first at 49 Brown St, which was the setting for 1990s cult film Scarfies, before buying their own home in Roslyn.
She worked at Mosgiel Knitwear and they ran the Rosslyn Gallery, then in Stuart St, for many years.
Mrs Janssen has two children, five granddaughters and six great-grandchildren.
Her husband, a time and motion engineer, died in 2009, aged 85.
Throughout her life she enjoyed lacemaking, embroidery, knitting and crochet.
She puts the dark parts of her life behind her.
"I can talk about it easily now, it doesn't affect me any more."
And she does not seem to have given up on life.
"I'll see you again when I'm 200."
This article was first published in the Otago Daily Times.
