The first years of her life, she lived in the Goedendagstraat in Borgerhout. When Maria was 7 years old, the family moved to Oostmalle, where she already started to write. She went to school at the "Heilig Graf" school for girls in Turnhout.
In 1933 the family moved to Essen and later to Kalmthout.
After three years of technical education she went to the College for Women in Antwerp. She started her professional career as a teacher at a school in Gierle, but she left the school to work, from 1941 up to 1944, at the department of internal affairs of the Ministry of Labor in Brussels.
In 1945 she became secretary at De Pijl, a publisher linked to the Flemish Catholic Scouts. In the meantime she made her first steps in journalism as freelance journalist for the "De Courant", a daily which appeared from 1937 until 1939.
In 1947 she became editor at the daily De Standaard where she would eventually become the movie critic and author of the woman page.
After her retirement in 1977 she continued working as a movie critic. Besides her journalism she created an impressive literary oeuvre. As a writer she created some important female characters.
First of all Elisabeth from the Elisabeth trilogy, of which the first part appeared in 1953.
As a Christian writer she drew attention with novels such as Ik was een christen (East: I was a Christian) (1957), Dood van een non (East: Dead of a nun) (1961. Movie in 1975 by P Collet en P Drouot) and Wacht niet op de morgen (East: Don"t wait for the morning) (1969).
Her best-known book was Dood van een non (1961), which was translated into several languages and was awarded on several occasions. Rosseels received an honorary Doctor of Philosophy from the Katholieke Universiteit Leuven in 1981.
She was knighted and became a Baroness in 1988.