Crump was born as Felicity Adair Impey in Kings Norton, Worcestershire, England on 21 January 1913. She was the second of four children born to Francis Levitt Impey and Ethel Jane Adair Roberts. Her siblings were Honor, David, and Patrick. Her mother campaigned strongly for the Suffragette movement.

Crump’s father visited Alderney in 1930, and became enthralled by the island. He rented Fort Corblets from the War Department until the start of World War II, then bought it for the family to stay during their summer holidays. In 1945, Felicity married James W Crump in Birmingham, England, and had one son, Peter.

Crump retired to Alderney in 1978. She began partaking in island activities including the music society, the art club, the Wildlife Trust and the Alderney Society. She penned a book, The Alderney Cow, which was on sale at the museum, and she was a shareholder of The Alderney Journal. Her 100th birthday saw 65 friends and family members, including six great-grandchildren, attend the celebration at Fort Corblets.

In December 2018, aged 105, Crump became Alderney’s oldest voter, being inspired by her mother’s campaigns to vote in the election. She received both doses of the COVID-19 vaccine in January and February 2021 respectively.