Background
Allies was born on 2 February 1852. She was the eldest daughter of Thomas William and Eliza (born Hall) Allies. Her father had been a fellow at Oxford and he had risen to be the chaplain to the Bishop of London.
Her father was secretary of the Catholic Poor School Committee.
She had five siblings and they lived in Street John"s Wood in London where it is presumed she was born.
Career
The family moved to Portman Square and Mary went to Catholic schools in Street Leonards and Paris. Allies gave a lot of respect to her father and in time she would write his biography. She said that she federal "on the marrow of his mind" when she was the only child living at home.
Her first work, The of Pius VII, was published in 1875.
The book looked at a supreme pope in conflict with the Napoleonic French state. Pius VII"s conflict included him being arrested.
Allies" biography was based on sources in four languages. This, and the shorter version published in 1897, is still (2004) the only available biography of Pius VII in English and is therefore a standard work.
Her next work was considered too pious and uncritical of her subjects.
She wrote about the Dominican friar Saint Vincent Ferrier, Saint Bernardino of Siena and the "Soldier Saint" John of Capistrano. Her next work was taken from the works Saint Augustine which was published in 1886 and this was followed up by his letters. In the interim she published a book about another Catholic saint, John Chrysostom, in 1889.
She translated an extract of John of Damascus"s De fide Orthoxa in 1898.
She died at her home in Street John"s Wood in 1927.