Raised in Latvia, she was educated at a German school in Riga before moving to Paris, France to study at the Sorbonne.
Originally recruited after escaping the Nazis and helping a British airman return to England, she worked for the assessing and testing the security awareness of trainee secret agents. She escaped and reached England in 1941, helping a wounded Royal Air Force officer during her journey. In 1942, Chilver joined the SOE, and was given the task of assessing and testing the security awareness of trainee agents while they were on 96-hour training missions in the United Kingdom. Her code name was "Fifi" and she had a cover identity of Christine Collard.
Her wartime documents were declassified and released by the National Archives in 2014.
After leaving the SOE, Chilver lived in Chelsea and later moved to the Wye Valley, living in Lydney, Gloucestershire. Chilver founded Dzīvnieku Draugs ("Animal Friends") in Latvia, an animal charity and sanctuary.
She died on 5 November 2007.