She was born in Kristiania, as the daughter of engineer Georg Monrad Krohn and actress Gyda Martha Kristine Andersen (later Gyda Christensen). Lillebil Ibsen took ballet lessons at an early age with her mother, who was a professional choreographer and ballet instructor.
She then studied ballet with Hans Beck in Copenhagen, and later with Russian choreographer Mikhail Fokine.
She made her début as a dancer at Nationaltheatret in 1911, in the ballet pantomime Prinsessen på erten, an adaptation of the story "The Princess and the Pea" by Hans Christian Andersen. She started performing in Berlin under supervision of Max Reinhardt when she was sixteen years old, and played leading roles in Reinhardt"s pantomimes Die Schäferin, Lillebils Hochzeitsreise, Prima Ballerina, Sumurun and Die grüne Flöte. She made her stage début as actress at Nationaltheatret in Kristiania in 1915, in the children"s comedy Den uskikkelige lille prinsesse.
Her first film role was in Sången om den eldröda blomman from 1918.
She made her début as a revue artist at Chat Noir in 1924. She worked at Det Nye Teater from 1929 to 1956, where she played classical comedy roles as well as a series of Ibsen characters, such as "Nora", "Mrs Alving" and "Gina Ekdal".
From 1956 to 1969 she performed at Nationaltheatret, where she played both dramatic and comic roles. She also played for the television theatre Fjernsynsteatret.
On film she does a stand-out performance in Arne Mattsson"s cult mystery thriller Mannequin in Red (1958).
Where Ibsen plays a large key part in a notable supporting role as the fashion house mogul Thyra Lennberg. Ibsen issued the autobiography Det begynte medical dansen. She died in Oslo in 1989.