Maria Domenica was born on 9th May 1837 at Mornese in the Alessandria region of Italy. In her family she received a grounding in solid piety, hard work and a remarkable common sense and judgement which stood her in good stead when she became a Religious Superior.
At the age of fifteen she enrolled in the Association of Daughters of Mary Immaculate and started to take part in apostolic work for the girls of the area. A serious bout of typhoid contracted when she was 23 had a profound effect on her spiritual development. This experience of being physically frail deepened her sense of abandonment to God, but also moved her to open a dressmaking workshop in order to teach girls about work, prayer and the love of God. Thanks to her devout sacramental life and the wise guidance of Don Pestarino she made great progress in spirituality.
When Don Bosco visited Mornese on 8th October 1864 she remarked "Don Bosco is a saint – I can sense it".
In 1872 Don Bosco chose her to help him found the Institute of the Daughters of Mary Help of Christians. As Superior she showed herself to be an able teacher and guide in the spiritual life. She had the gift of serene and comforting cheerfulness, radiating joy and drawing other young people to dedicate themselves to the education of girls.
After her death the Institute continued to develop rapidly. She left her Daughters a style of education permeated with gospel values: the search for God, known through enlightened teaching and fervent love, responsibility in work, openness and humility, austerity of life and joyful self giving.
She died at Nizza Monferrato on 14th May 1881. Her body is venerated in the Basilica of Mary Help of Christians in Turin. She was canonized on 24th June 1951 and her feast is celebrated on 13th May.