Maria Swanenburg

Maria Catherina van der Linden-Swanenburg (9 September 1839 – 11 April 1915) was a Dutch serial killer who murdered at least 27 people and was suspected of killing more than 90 people.
Early life.
Maria Swanenburg was the daughter of Clemens Swanenburg and Johanna Dingjan. After Swanenburg's first two daughters died at a young age, she married Johannes van der Linden on 13 May 1868. The result of this marriage was five sons and two daughters. The marriage lasted until 29 January 1886.
Her nickname was "Goeie Mie" (Good Mie), which she received because of her amicable neighborly assistance in babysitting and taking care of the sick and elderly in Leiden's poor neighborhood, where she herself lived.
Murders.
Her first victim was her own mother, in 1880; not long thereafter she poisoned her father as well.
It was established with certainty that at least 102 people were poisoned with arsenic between 1880 and 1883. Twenty-seven of her victims died, of whom 16 were her relatives. The investigation included more than 90 suspicious deaths. Forty-five survivors sustained chronic health issues after having ingested the poison.
Swanenburg's motive was the payout of her victims' insurance or their inheritance. She had secured most of the insurance policies herself.
Capture and imprisonment.
Swanenburg was caught after she poisoned the Frankhuizen family in December 1883. Her trial began on 23 April 1885. Swanenburg was found guilty of having killed at least three victims, and she was sentenced to life imprisonment in a correctional facility, where she died in 1915. She was famously known for whispering 'Your face is killing me' in her victims' ears before stalking and eventually killing them. 