As with many German Jews, the true menace behind the Nazis' intensifying persecution only dawned on Helga's family when her uncle was arrested during the Kristallnacht anti-Jewish pogrom on November 9, 1938.
After his release from a brief internment in a concentration camp, Helga's uncle was adamant the entire family should get out of Germany while they still could. "He said to my mother she had to send me away, that there was no life for me here," she remembers.
Within a few months, Gertrud had secured her daughter, then aged 18, papers and a passage on a ship to Britain. But she would have to go alone, with only a few suitcases and some petty cash to her name.
"It was terrible," says Helga. "My mother went alone to take me to Hamburg. We couldn't find anywhere to have lunch, the 'Jews not allowed' signs were everywhere." It was April 19th, 1939, the day before Hitler's 50th birthday. She never saw her mother again.
Gertrud did not leave Berlin, even as many close relatives fled to Shanghai, one of the few remaining destinations still at that time accepting German Jewish refugees without visas. "My uncle went with my grandmother to Shanghai. He wanted to take my mother with them but she said: 'Now there's a war on, Hitler won't have time for the Jews, he will be too busy,'" says Helga.
Living alone in London and working as a maid for a British family, Helga could guess little of her mother's impending fate. In the intervening years they exchanged heavily self-censored letters sent via a convoluted postal route, first through Belgium, later via America.
"My mother couldn't say much in the letters," says Helga. "She knew they would be opened and read. I found out from a friend's mother that my mother had been taken. But I didn't know any details until the war was finished."
On August 15, 1942 the Gestapo came to Güntzelstraße to arrest Gertrud, then aged 47, taking her first to be registered at an assembly point at a synagogue in Berlin Mitte. From there she was transferred to Bahnhof Moabit, where a train was waiting to take her and 1003 others to their final destination, Riga. On arrival, the records show Gertrud and the others were then led into a forest and shot by firing squad.
"A person is only forgotten when their name is forgotten," Berlin artist and Stolperstein conceiver Gunter Demnig is often quoted as saying. 5000 of the tiny memorials have been laid on capital's streets since 1996, marking the last residences of some of the city's murdered Jews, homosexuals, Roma and Sinti along with the Nazis' political and religious opponents.
Helga and her family left Berlin that evening after a whistle-stop tour of the Jewish museum, Weißensee graves and the Holocaust memorial, hoping the new Stolperstein will cement the name of their murdered relative in the city she spent her whole life.
In decades to come the shiny brass plate on Güntzelstraße will still catch the eye of some curious passerby. Bending down to read the inscription, they will see the name Gertrud Kirsch, a small act of defiance against those who wished to wipe her and so many others off the face of the earth.