Answer
The movie in question is called "Princess O'Rourke". It is a 1943 film directed by Norman Krasna and starring Olivia de Havilland, Robert Cummings, Charles Coburn, and Jack Carson. The film tells the story of a princess who escapes her royal life and disguises herself as a commoner to experience life outside the palace. She meets a handsome reporter and falls in love with him, leading to romantic complications.