Elizabeth Tyldesley born in 1585, was the daughter of Thomas Tyldesley of Morleys Hall, Astley and Myerscough Hall and Elizabeth Anderton of Lostock, in Lancashire (now Greater Manchester). Her family were recusants and her mother arranged a pension for the Roman Catholic priest, Ambrose Barlow, so that he could secretly carry out priestly duties, offering Mass in the homes of Roman Catholics in the Leigh parish.
Instead Elizabeth joined the English community of nuns of the Order of Saint Clare, then called "Claresses", at Gravelines, at that time part of the Spanish Netherlands. The Poor Clare Convent at Gravelines was a religious community founded in 1607 by Mary Ward for English Roman Catholic women who wished to live the contemplative life of a nun, which was impossible after the Reformation and its consequence, the Dissolution of the Monasteries. Elizabeth was one of seven candidates who received their religious habits on 5 February 1609.
She assumed the name of Sister Clare Mary Ann when she received the habit.
She completed her novitiate year and professed her first vows 3 November 1610. Five years later, she was elected abbess of the community.
Previous incumbents of that office had struggled with financial difficulties, but under Mother Clare Mary Ann the establishment flourished. Elizabeth died on 17 February 1654 after 44 years in the monastery, of which she had served as abbess for 39.
