Saturnina Jassá y Fontcuberta was born in Spain on March 3, 1851 in Calaceite, an Aragonese municipality then belonging to the diocese of Tortosa in the province of Teruel. After a normal childhood and youth, Saturnina, a very religious girl, in 1874, at twenty-three, entered the Archconfraternity of Santa Teresa where she met Father Enrico de Ossó y Cervelló. Three years later, on May 4, 1877, she entered the "Company of St. Teresa of Jesus", a religious congregation  founded by Father Enrique.

In the same year she was sent to represent her congregation on the Teresian pilgrimage to Avila and Alba de Tormes. She obtained the title of elementary teacher and in the following year that of high school teacher. On January the 1^st, 1879, she pronounced her religious vows in the hands of the founder and took the name of Saturnina of the Agonizing Heart of Jesus. On the 12^th of October 1879, she was appointed Superior and Mistress of Novices in the Tortosa community. After all the religious of the congregation made their perpetual profession, Sister Saturnina was elected Superior General of the congregation. After her seven years as superior, in 1889 she was assigned to Mexico to found the various houses of the congregation and where she was a teacher in Puebla and in 1893 Superior in Chilapa. Moreover, in Mexico, for three years she was entrusted with the direction of the nascent congregation of the Religious of the Cross of the Sacred Heart..

In the new congregation she had the opportunity to witness to her great gifts and virtues through immense sacrifices. In 1900 she returned to the Company of Santa Teresa and was immediately appointed Superior of the Valencia house. In 1904 she became Provincial in charge of the Sacred Heart Province and in 1906 Superior of Ciudad Rodrigo community. Re-elected Superior General in 1908, she remained in that role for twelve years, proving to be a nun with a strong personality, who knew how to guide the Institute in absolute fidelity to the intentions of the founder. In 1920, she was appointed General Councillor of the Congregation, in that year she retired to the novitiate of Jesus (Tortosa).

She died in the odour of sanctity on October 13, 1936, in Tortosa.

The decree of heroic virtues was promulgated on March 3, 1990, and she was declared Venerable.