She studied at the Dagtekenschool voor meisjes [nl] (English:Day drawing school for girls) .

She studied under Jan Hanau, Wilhelmina Cornelia Kerlen, Cornelis Kuypers [nl], Piet Mondrian, and Piet van Wijngaerdt [nl].

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

[2] She exhibited regularly with Kunstenaarsvereniging Sint Lucas [nl] from 1911 through 1944 and with De Onafhankelijken from 1919 through 1960.

[5] In 2015 The Mondriaan House held an exhibition Agatha Zethraeus - Vriendin, leerling en model van Piet Mondriaan (Agatha Zethraeus - Friend, pupil and model of Piet Mondrian).