Lydis exiles in Buenos Aires looking for peace and although she arrives a month before the arrangements for the exhibition in august at the Müller Gallery, she does not travel through South America. This fact will lead her to travel in the following years to Rosario, Córdoba, the north of Argentina and Uruguay, linking her with poets and artists who review the identities that shape Argentina, the autochthonous regions and the dehumanization caused by the disasters of war, in a country which lives it at distance.
In the exhibition that Lydis performs at her arrival, the artist presents a set of twenty paintings and thirty-two drawings with good reception from the critics who remark her drawings, with the exception of the German pronazi newspaper published in Argentina, the Deutsche La Plata Zeitung (DLPZ ) which makes a cold compliment of Mariette's drawings: "they are often lost, with problems, even despondent", and continues, [...] with "decadent tendencies and unhealthy intellectualism", or "games with faces of young prudish people or lascivious flirting ". The high society of Buenos Aires enthusiastically welcomes the enigmatic and aristocratic Countess Govone, her title and her glamor contribute to the fascination for her person. Lydis, on the other hand, constantly shows her reserve of talking about her life, family, age, marriages and nationality, Mariette in the first forties, still lives as a foreigner, a refugee of a war that although distant still does not stop, nevertheless she maintains epistolary bonds with Carmen Jaubert, her marchand in Paris and strengthens her contacts in England. With the help of her friend Julia Bullrich de Saint, Lydis bought an apartment in Buenos Aires on the top floor of a building at Cerrito street, where she sets up her atelier looking for a new space to work, waiting for a future reunion with Giusspepe Govone who finally travels in 1945 residing with her in Buenos Aires until 1948, when he returned to France and died. At that time Count Govone edited in Buenos Aires, Doce cuentos de Guy de Maupassant illustrated by Mariette and began the illustrations of Madame Bovary that were finally published with the editorial of Jacques Vialetey in 1949. Between 1948 and 1949, and for eleven months, Berlin was blocked by the Soviet Union. Once again seeing her quiet disturbed, Mariette returns to Buenos Aires in January 1950, on board of the Conte Grande.
From 50´ onwards Mariette Lydis illustrates the titles of Colette, Louÿs, Verlaine, Baudelaire, with other French editors such as Georges Guillot and Alphonse Jolly. Between 1940 and 1970 at least twenty-two books were published in France and more than seven in Argentina. She travels sporadically between 1955 and 1959 carrying out exhibitions in Europe. In 1955, in the Paul Ambroise Plaquevent gallery, after five years of absence, and in 1956 in Rome, in the Sagittario Gallery and in Milan, in the Guido le Noci gallery.