Isabel de Salles Penteado was born at Fazenda Santa Rosa, situated along the banks of the Piracicaba River in São Paulo, Brazil, on 3 June 1894 (claimed 3 July 1893). She was the daughter of Luiza Müller, a widowed seamstress, and Manuel de Moraes Barros, a senator for the State of São Paulo from 1895 to 1902. Her father was the brother of Prudente de Morais, who served as the third president of Brazil. She was adopted by José Gabriel de Mattos and Gertrudes Silveira Mattos, a couple who were friends of her father and owned a farm. However, she maintained contact with her biological father’s family.

When she was 10 years old, her adoptive father passed away, prompting her and her adoptive mother to relocate to the city of São Paulo. Having already learned French at school, she began studying piano with Maestro Luigi Chiaffarelli. It was during this time that she developed a taste for Chopin, Schubert, and romantic writers. She even read Victor Hugo and Alexandre Dumas in their original languages.

As a young woman, she met António de Salles Penteado, who would later propose to her at a costume ball in 1916. Her initial response was, “Only if you ask on your knees.” The couple went on to have nine children: Guiomar, António, José Gabriel, Maria Cecília, Mario, Lucia, Ruy, Odilion, and Maria Helena. One of her sons, Antônio Penteado Neto, also known as Pentedinho, served as an aviator for the Brazilian Air Force (FAB). He lost his life in an accident during an instructional flight with a novice.

She participated in the Constitutionalist Revolution of 1932, a movement in São Paulo against the Brazilian Revolution of 1930, which marked Getúlio Vargas’s assumption of the nation’s presidency. During this period, she contributed by sewing uniforms for the São Paulo Army and working in the field kitchen near the trenches. According to her youngest son, she narrowly avoided danger when a rifle shot pierced her skirt between her knees but didn’t hit her. In another situation, she restrained a man running during a rally before the Constitutionalist Revolution erupted into gunfire. Later, she discovered that the young man was Paraguayan and had no connection to the uprising.

Throughout her life, she forged friendships with notable individuals such as the poet Guilherme de Almeida, the writer Paulo Duarte, and the pianist Guiomar Novaes.

In January 2004, at the age of 109, she had 60 great-grandchildren and 4 great-great-grandchildren. She was known as “Dona Bebé.” At some point, she moved to the Lar Nossa Senhora das Mercês nursing home in Alto de Pinheiros.

Isabel de Salles Penteado passed away in the city of São Paulo, São Paulo, Brazil, on 23 January 2005, at the age of 110 years, 234 days.