She was the daughter of José Osório Cabral de Alburquerque, lieutenant-general and governor of the Portuguese colony of Macau, and of Ana Doroteia Rosa Moor Kintins, a Dutch national.

[1][2][3][4] After getting married, Osório de Castro lived for 22 years in Mangualde in Portugal's Viseu District, where her husband was then a property registry officer.

Osório de Castro played a prominent role in the management of the Association and contributed to the promotion of its ideas, particularly after the death of Carolina Beatriz Ângelo and during the period in which her daughter and Elzira Dantas Machado travelled to Brazil.

In the same year, she joined the Women's Commission "For the Fatherland", and worked to collect clothing and supplies for Portuguese soldiers deployed during the First World War.

During the same period, she joined the Maternal Work initiative, managed by Inês da Conceição Conde and Maria Veleda, which aimed to rescue children from the streets.