Flandrin was born in Saint-Siméon, Orne, France, on 22 January 1913. The commune of her birth merged into the new commune of Passais Villages on New Year’s Day 2016. Flandrin never married nor had children.
Flandrin’s older sister, Yvonne Prodhomme, lived to be 109 years, 133 days old. The pair have a combined age of over 219 years, the third-highest in known French history. Their younger sister, Simonne Guesdon, died aged 103 years, 268 days. The trio have a combined age of over 323 years, the second-highest in France.
Flandrin, a private person, died in the commune of Le Bar-sur-Loup on 8 March 2023 at the age of 110 years, 45 days.