She was born in Arnhem as the daughter of an English teacher, and on her mother's side was the niece of the abstract painters Jacob Bendien and Paul Citroen.

After a short period working as assistant for the director of the Royal Academy in The Hague, a position she obtained through her uncle Citroen, the war broke out.

de Boer on an ad hoc basis with the set up of exhibitions, while starting to deal in art prints on the side, helped by her uncle Citroen.

Her marriage broke up 5 years later and she moved with her son to Heemstede, where her friend Polly Meurs was living with her husband the painter Jules Chapon.

[2] The archives have letters and receipts for early works by Anton Heyboer, Reinier Lucassen, Roger Raveel, Lucebert, Wessel Couzijn, Pierre Alechinsky, Jules Chapon, Corneille, Hugo Claus, Klaas Gubbels, Kees Okx, Pearl Perlmutter, Carel Visser and Karel Appel.