Her formal painting education began at the Royal Academy of Visual Arts in The Hague.

She learnt about etchings and lithography from Auguste Morisot [fr] at the École nationale supérieure des beaux-arts de Lyon.

Her oeuvre is varied: portraits, various types of still lifes, genre, figure and animal performances.

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

She married in her home town in 1892 to the painter and mechanical engineer Evert Cornelis Ekker [nl].