During World War II, she operated a safe house out of her home for a group of young Jewish people in one of the apartments at the Herengracht 401, in the center of Amsterdam.

In 2019 a report was published by former judge Frans Bauduin about years of structural sexual abuse conducted by Wolfgang Frommel in the house of Gisele.

[3] Van Waterschoot spent the first three years of her life in the Netherlands, and then she and her family relocated to the United States due to her father’s work.

Her examination piece, a large print after a self-portrait by Jean-Honoré Fragonard entitled L’Inspiration, gained her a Mention Honorable, Section Gravure at the 1931 Salon.

Her work was included in the 1939 exhibition and sale Onze Kunst van Heden (Our Art of Today) at the Rijksmuseum in Amsterdam.

For the duration of the war, van Waterschoot secretly housed several people in her apartment including Wolfgang Frommel (a German poet, who was a former member of the Sturmabteilung, the paramilitary wing of the German Nazi Party), Jewish teenager Claus Victor Bock, Jewish writer Friedrich W. Buri, and others.

[10] While in hiding, the group of artists and writers codenamed their shelter "Castrum Peregrini" and covertly studied art and literature.

After the end of World War II, van Waterschoot bought the apartment building to convert to a single home where she lived and worked on and off for the rest of her life.

In June 1945, she was reunited with Ides in Amsterdam, who had served as a highly ranked officer in the American army during the liberation of Europe.

[14] van Waterschoot was friends with artist Max Beckmann and stored some of his paintings during his long period of exile from Germany.

[4][5][6][12] Starting in the 1960s until the 1980s, van Waterschoot spent several months each year painting and doing restoration work at an old monastery on the Greek island Paros.