Szekely-Lulofs was born on 24 June 1899 as Madelon (Magdalena) Hermine (Hermina) Lulofs in the Oranje Hotel in Surabaya on the island of Java (then Dutch East Indies now Indonesia).
She was the eldest daughter of Claas Lulofs, a civil servant in the Dutch East Indies and Sarah Christina Dijckmeester, whose families both originated from Deventer, Netherlands.
When her husband discovered her adultery, he sent her and her daughters for one year to Australia, but when Madelon returned to Deli in 1925 she still was in love with Székely.
Before the 1930s planting of rubber in the Dutch East Indies reached a peak, but in 1930 disaster struck and many people in that industry lost their jobs and faced bankruptcy.
In the 1940s Székely-Lulofs published some new books, but in the fifties she produced mainly translations into Dutch, from English by Pearl S. Buck and Margaret Campbell Barnes, but also from Hungarian (Zsolt Harsányi, Jolán Földes) and German.
Coolie is a story how young healthy Javanese were shanghaied to trick them into working for the rubber plantations in Sumatra.
De andere wereld ('The Other World') is a 1934 novel about a poor downtrodden boy from Amsterdam, Pieter Pots, who gets a job on a rubber plantation in Deli, Sumatra and the world he is going to live in as a colonial white skinned person compared to the very poor life he has led in Amsterdam.
It describes the war between the local people and the Dutch colonial power in the period 1873-1914, of which the difference in religion also played a part.