She was the stepmother from hell killing her stepchildren by painting the backs of their throats with hydrochloric acid. There was nothing in it for her she just didnt want to care for the kids any longer.
Anne Morris, nine, died from a severe throat infection; Olive, seven, died of a similar illness, and a year later, in 1908, 15-year-old Arthur died the same way.
When a fourth child ran away, complaining of a sore throat, police in Perth, Western Australia, looked into the cases and ordered exhumations. The wicked stepmother, Martha Rendell, was promptly arrested, sentenced to death in September 1909 for all three child murders, and hanged on Wednesday, October 6th, 1909, in Fremantle Prison.