Irías was born in Danlí, El Paraíso Departament, Honduras, on 25 April 1915, to parens Juan Antonio Irías and María Otilia Alvarado. She was the oldest of five siblings. At the age of 10, she lost her mother, and she and her siblings were subsequently raised by their paternal aunt, Julia Irías. She attended the Pedro Nufio School, and even in her centenarian years, she was able to remember her teachers, Ernestina Zelaya and Brígida Ortiz. She completed five grades there. After school, she learned to sew from her godmother, Elvia Castellanos, who was one of the best seamstresses and wedding dress designers in Danlí throughout much of the 20th century. At the age of 20, she got a job at a store owned by the novelist Lucila Gamero de Medina, where she worked for four years. Her daughter Nelly recalled that Gamero encouraged her to read while she was employed there, and this habit of reading stayed with her even into old age.

On 12 October 1946, at the age of 31, she married José Morga Vallecillo. The couple had three children: a son who died at the age of 2, and two daughters, Nelly and Dilcia. Her husband died in 1988.

When asked about the secret of her longevity and lucidity in old age, she attributed it to “knowing how to live, getting along with others, maintaining good eating habits, and relying on God every day because He is the one who gives us life and the strength to live.” At the age of 103, besides reading, she enjoyed watching television, particularly religious programs such as masses and messages from a Mexican preacher, which were her favorites. She is also a member of the Legion of Mary.