[1] Ann was born in Rosliston,[2] Derbyshire, the daughter of a day-labourer and sawyer, William Peg (or possibly Pegg), in 1761.

After the separation, Ann returned to work as a housekeeper for a widowed farmer in Aston, near Tutbury, where she had two more children by her employer.

On 20 May 1807, it was reported that she attempted to swallow a piece of biscuit, but the effort was followed by great pain and vomiting of blood.

Religious prophet Joanna Southcott declared that the advent of the fasting-woman presaged a three years' famine in France.

Robert Taylor and John Allen, two local doctors wrote about the case to the Edinburgh Medical and Surgical Journal[4] in November and December 1808.

Mary said that she could only think of the following poem: "There was an old lady all skin and bone This old lady was very well known She lay in bed as I've heard say For many years to fast and pray When she had lain a twelvemonth's space The flesh was gone from hands and face When that another twelvemonth was gone She was nothing at all but a skeleton"[5] In the summer of 1812, Alexander Henderson (1780–1863), Physician to the Westminster General Dispensary, wrote an able Examination of the imposture,[6] showing the inconsistencies and absurdities of the woman's statements, and the curious parallel between the case and that of Anna M. Kinker, a girl of Osnabrück, who practised a similar imposture in Germany in 1800.

[6] In 1813, Ann reluctantly agreed to another watch, this time supervised by local writer and clergyman Legh Richmond.