In 1974 Caeiro was working in a self-service restaurant in
Lisbon called "Sir" located at Franjinhas Building on Rua Braamcamp as a cleaner. The restaurant was opened on 25 April 1973 and for its first anniversary, on 25 April 1974, the owners planned to give out red and white
carnations to all its customers and which were bought in Ribeira square by the owner of the restaurant. The pictures of the soldiers with carnations in their guns appeared on front pages all over the world and the coup became known globally as the Carnation Revolution and signalled the transition from a military coup to a peaceful and bloodless revolution. Since then, every year, around 25 April, she was given time off work so that she could give interviews. On 7 May 1974, journalist wrote in the newspaper
República that "the red carnation of Freedom has no known author, it was not proposed or programmed by any organisation. It is anonymous and natural like everything that is alive". Later, , in
Crónica Feminina, described Celeste's gesture with a poem and as a symbol of freedom: "In a few days, the carnation became the symbolic flower of a country... The first hand that knew how to place it tenderly in the barrel of a rifle... It was a woman—if it is a woman—that someone has the right to an immortal statue." Celeste's testimony is also well detailed in Ana Sofia Fonseca's book
Capitãs de Abril. In 2024, she took part in the parade commemorating the 50th anniversary of the Carnation Revolution on Avenida da Liberdade in Lisbon alongside her daughter and granddaughter. Celeste Caeiro's presence on Avenida da Liberdade was one of the most memorable moments of the popular celebration. At the solemn session that day in the
Assembly of the Republic, the deputy
Rui Tavares suggested that a statue of Caeiro be erected in the Assembly building. ==Personal life and death==