Josefina Netto da Silveira was born in Lamim, Minas Gerais, Brazil, on 22 March 1902, to parents Luiz Gonzaga de Assis (1861–1951) and Adelaide Netto de Assis (1869–1927). She had at least 11 siblings, including Joana d’Arc Netto de Assis (1908–2012), who died at 104.

She was the maternal granddaughter of Dr. José Francisco Netto (1827–1886), who was granted the title of Baron of Coromandel by Dom Pedro II in recognition of the medical services he provided during a smallpox outbreak that struck the state. On the family farm, they produced milk and cachaça (a traditional Brazilian sugarcane spirit). At the manor house, and later at the Immaculate Conception College in Barbacena, she learned to read and write, dance, sing, play the guitar, embroider, and sew.

On 22 February 1930, at the age of 27, she married Jacob Nogueira da Silveira in Rio Espera. A trained dentist, Jacob devoted himself to business and public service, working as both a merchant and a city councilman. Together they had three sons—Aloísio, José, and Geraldo—and adopted a daughter, Nazinha. In the late 1950s, after Jacob accepted an invitation from a friend to work in São Paulo, Josefina left Minas Gerais with her family. The couple and their four children settled in the city of São Paulo. Jacob died in 1982.

She passed away in Mooca District, São Paulo, São Paulo, on 24 March 2015, two days after her 113th birthday.