Kate Tucholla played hockey for her school team and for the Sparta Lichtenberg club, which was part of the German workers' sports movement. There she met the soccer player Felix Tucholla, her future husband. Felix Tucholla was active in the Communist Party of Germany, he introduced Käthe to political engagement. Both became members of the Combat Community for Red Sports Unit.
When the National Socialists came to power in Germany, Käthe and Felix Tucholla and the anti-fascist resistance group around Robert Uhring took part in the dissemination of illegal anti-fascist literature and the procurement of quarters for persecuted anti-fascists. Käthe Tucholla was also a courier driver in other German cities. In addition, they both supported the Soviet agent Erwin Panndorf, who had parachuted over East Prussia in May 1942.
On July 25, 1942, Käthe Tucholla was arrested by the Gestapo in her apartment at Kaskelstrasse 41, and on July 28, Felix Tucholla was also arrested. Both were sentenced to death by the Peoples' Court on August 17, 1943. The sentence was carried out on September 28 and 8, 1943, in Berlin Plotzenses prison.