Plaat-Kolenbrander was born in Utrecht on 6 January 1898 as the second child of Andries Jacobus Kolenbrander and Gijsberta Antonia Beuker, who lived to be 79 and 73 respectively. Her three younger brothers, Jan Gerrit, Jan Frederik, and Gijsbertus, all died in infancy, while her older brother Andries lived to 96, and her younger sister Hillegonda to 91.

On 2 September 1921, aged 23, Plaat-Kolenbrander married Jacob Dirk Plaat in The Hague, South Holland. The couple had two children. Her husband died in 1965 aged 70 after 43 years of marriage.

Following the 19 May 2006 death of 111-year-old Alexandrina Van Donkelaar-Vink, Plaat-Kolenbrander became the second-oldest Netherlands resident, after Grietje Jansen-Anker. She died on 9 March 2008 aged 110 years, 63 days.