After contributing to Swedish newspapers from Berlin in 1907, she worked for Svenska Dagbladet first in Sweden and later as a foreign correspondent in Vienna where she lived from 1923 to 1933.
Marcus was a key figure in the Swedish branch of Save the Children which she helped to establish in 1919, continuing her support during and after the Second World War.
[1][2] While working in Berlin in 1907, she began to send news reports to Swedish newspapers such as Dagens Nyheter, almost accidentally becoming a foreign correspondent.
After it closed in 1913, she joined the editorial staff at Svenska Dagbladet, eventually working in Vienna as the paper's foreign correspondent.
During the difficult years of the First World War, thanks to her writings and support from the newspaper, she was able to raise substantial funding for the elderly to enjoy holidays and for children to take part in games and other organized activities.