She also took an evening course in stenography and at the age of twenty went to work as a secretary at the Hollandsch Weekblad, a periodical intended for Dutch people living in Belgium,[2] for which she managed the administration and advertisements.

In addition, Dubois wrote in Dutch and French for the publisher of the magazine Libelle, also based in Haarlem.

In 1952, after a suggestion from her husband[4] she discovered the work of Belle van Zuylen (1740–1805), the Dutch writer who wrote in French, after reading a biography by Philippe Godet.

[7][8][9] On the advice of Leendert Brummel, emeritus professor of Library Science at the University of Amsterdam, Dubois became a member of the 18th Century Working Group in February 1970 in order to get to know other people interested in Van Zuylen, better known in French by her married name as Isabelle de Charrière.

With the working group, she organised the international congress Actualité d'Isabelle de Charrière in Zuylen Castle in September 1974.

[12][13] In 1990, she and her husband retired as board members of the Belle de Zuylen Society to fully focus on writing the biography.

Eventually, together with her husband, she wrote the more extensive biography of Belle van Zuylen, Zonder Vaandel (published 1993), based on the Collected Works and their research.