In 1944, Ulrika Marseen becomes a student of sculptor Henry Luckow-Nielsen and subsequently of Johannes C. Bjerg, who is a professor at the Royal Danish Academy of Fine Arts at the same time.

Marseen makes her debut at the Artists' Autumn Exhibition in 1945. She exhibits there several times thereafter, as well as at the Salon des Surindépendants in Paris 1947–49, and at Charlottenborg's Spring Exhibition in 1953–54. In 1948, she becomes part of the artist group Spiralen, whose members also included Mogens Balle, Knud Nielsen and Wilhelm Freddie. She submits her monument contribution to the international competition The Unknown Political Prisoner in 1952 and is included in the selected group, which is subsequently exhibited at the Tate Modern in London.