Elizabeth Brownrigg was born around 1720 into a working-class family. As a teenager, she married James Brownrigg, an apprentice plumber. The couple had sixteen children, though only three survived infancy. By 1765, the family had moved to Flower de Luce Court on Fetter Lane in London. James established a successful plumbing business, and Elizabeth gained respect as a midwife. Her reputation led to her appointment by the parish of St. Dunstan's to oversee women and children, resulting in her taking in several apprentices from the London Foundling Hospital to serve as domestic servants.

Between 1765 and 1767, Elizabeth Brownrigg subjected her female apprentices to severe physical abuse. She often stripped them naked, chained them to beams or pipes, and whipped them with various implements for minor infractions. One apprentice, Mary Jones, managed to escape and reported the abuse to the Foundling Hospital, prompting a warning to Elizabeth. Despite this, the mistreatment continued with other apprentices, including Mary Mitchell and Mary Clifford.

Mary Clifford endured particularly brutal treatment. She was kept naked, forced to sleep on a mat in a coal hole, and was fed only bread and water. When she attempted to take food, Elizabeth beat her for an entire day while she was chained to a roof beam. By June 1767, both Mary Mitchell and Mary Clifford suffered from infected, untreated wounds due to the continuous assaults. Neighbors grew suspicious and alerted the Foundling Hospital, leading to an investigation. While Elizabeth released Mary Mitchell, she attempted to conceal Mary Clifford. Authorities eventually discovered Mary Clifford in a cupboard, severely injured and malnourished. She was taken to St. Bartholomew's Hospital, where she died from her injuries.

Elizabeth and her son John fled but were apprehended in Wandsworth after being recognized. In August 1767, Elizabeth was tried at the Old Bailey. Witnesses, including Mary Mitchell and medical examiners, testified about the abuse. Elizabeth was found guilty of murder and sentenced to death. Her husband and son were acquitted of murder but later found guilty of abusing Mary Mitchell and sentenced to six months in prison. Elizabeth was executed by hanging at Tyburn on 14 September 1767. Her body was publicly dissected, and her skeleton displayed at Surgeons' Hall as a grim reminder of her crimes.