Arp interested her in the literature of Lautréamont, Rimbaud, and Jarry, and persuaded her to attend the 1925 Surrealists exhibition in Paris.
Their home became a meeting-place for modern artists such as Hans Arp, Sophie Taeuber-Arp, Kurt Schwitters and Max Ernst.
A year before her death in 1946, Paul Klee's widow Lily Klee specified in her will that the care of her husband's artistic estate should be overseen by a commission that was to include her son, Felix Klee, Carola Giedion-Welcker, and the Bern collectors Werner Allenbach, Rolf Bürgi, Hans Meyer-Benteli and Hermann Rupf..[2] Giedion-Welcker published about 280 articles in magazines on modern painting, sculpture and poetry.
She also wrote 17 books, including Moderne Plastik, Poètes à l'Écart and the anthology Schriften 1926–1971, published in 1973 by Reinhold Hohl.
It showed how as an art historian, author, and curator, she shaped the cultural life of the city and influenced the gallery's purchasing policy.