María Delfina Cuellar Venegas was born in Torreón, Coahuila, Mexico, on 24 December 1910 (claimed 1909). She had six siblings.
On 26 May 1931, she married Victor Coronado Rangel. The couple had 12 children. Her husband died in February 1985, at the age of 75.
Maria Delfina Cuellar Venegas died in Mexico City, Mexico on 29 August 2022, at the age of 111 years, 248 days.
Her age was verified by Fabrizio Villatoro and Stefan Maglov, and validated by the LAS on 27 December 2020.