Dighero was born in Lavagna, Liguria, Italy on 24 December 1891. She married Giobatta Zolezzi and had two sons, Giacomo and Attilio. She was widowed in 1984 when her husband died aged 89.
On Christmas Eve 2005, Dighero celebrated her 114th birthday in the company of her two children, who were 83 and 80 years old respectively. To mark the occasion, she was visited by the mayor of Lavagna, Giuliano Vaccarezza, and received a telegram from then-President Carlo Azeglio Ciampi.
Dighero died of ischaemia in her hometown of Lavagna on 28 December 2005, four days after turning 114. At the time of her death, she was the seventh-oldest validated living person in the world.
Dighero’s age was verified by Giovanni Alunni and validated by the GRG on 9 July 2003.
On 14 May 2003, following the death of Teresa Fumarola, she became the oldest living woman in Italy. On 19 June that year, she became Italy’s oldest living person after the death of Giovanni Frau.
On 6 June 2005, she broke Fumarola’s age record for Italy residents. On 30 August that year, she became Europe’s oldest resident upon the death of Hendrikje van Andel-Schipper, and on 14 September, she became the oldest Italian ever after surpassing Amalia Barone’s age.