Bertha was the daughter of Meijer de Groot and Ida Wijnberg. Her first marriage with Gerrit Helmus van der Veen was dissolved in Middelburg in 1907. Ten years later, at the age of fifty, Bertha married again. Her second husband was Pieter Coenraad van der Kuijp, a Holland America Line (HAL) steward. He died in 1926.
Bertha initially worked as a shop saleswoman, and later as a trader. As a widow an…