Elizabeth Branch, née Parry, was born in 1672 in Philips Norton, Somersetshire, England. She was the youngest daughter in her family. Her father, a ship's surgeon, later became a shipmaster, amassing a considerable fortune. Elizabeth married Benjamin Branch, a landholding farmer, and received a substantial dowry from her father. The couple had at least one daughter, Mary, also known as Betty. 

Following Benjamin's death in 1730, Elizabeth and Mary managed the family estate, which provided them with an income of approximately £300 per year. During this period, both mother and daughter developed a notorious reputation for cruelty, particularly towards their servants. Their violent behavior was so extreme that it became difficult for them to retain household staff, relying instead on individuals placed by parish authorities or transient workers. ​

On 13 February 1740, Elizabeth and her daughter Mary accused their 13-year-old servant, Jane Buttersworth, of loitering during an errand to fetch yeast. Upon her return, they subjected Jane to a brutal assault lasting nearly seven hours. Witness Anne Somers, the dairymaid, testified that Mary struck Jane on the head, pinched her ears, and, along with Elizabeth, threw her to the ground. Mary knelt on Jane's neck while Elizabeth whipped her with twigs until she bled. Mary then beat Jane with her own shoe and, after Jane attempted to escape into the parlor, both women continued to beat her with broomsticks until she lost consciousness. Mary doused Jane with a pail of water in a further act of cruelty. Somers, upon returning from milking cows, found Jane dead on the floor, her body having been cleaned and repositioned.

The Branches attempted to conceal the crime by secretly burying Jane and claiming she had died of natural causes. However, suspicions arose in the community, leading to the exhumation of Jane's body. A local surgeon's examination revealed severe injuries, including wounds that would have been fatal to even the strongest individuals. Elizabeth and Mary were arrested and tried for murder at the Somerset assizes on 31 March 1740. The jury found them guilty without retiring to deliberate. Due to fears of public unrest, their execution was conducted early in the morning on 3 May 1740 at Ilchester, attended by only a small number of officials to minimize the risk of mob violence.