Felícitas Sánchez Aguillón was born in 1890 in Cerro Azul, Veracruz, Mexico. From a young age, she exhibited troubling behavior, reportedly poisoning street dogs during her childhood. She pursued a career in nursing and midwifery, eventually moving to Mexico City in 1910 after divorcing her first husband, Carlos Conde, with whom she had twin daughters. The dissolution of her marriage was precipitated by her decision to give up their daughters for adoption without her husband's consent.

Upon settling in Mexico City, Sánchez Aguillón established herself as a midwife and began performing illegal abortions. Operating from her apartment in the Colonia Roma neighborhood, she also engaged in baby farming, selling infants to childless couples or, when unable to sell them, resorting to murder. Her methods of killing included poisoning, strangulation, and dismemberment. She disposed of the bodies by incineration or discarding them in the sewer system.

Her crimes came to light on April 8, 1941, when human remains were discovered near her residence. Authorities arrested her on April 11, 1941, along with two accomplices: her second husband, Roberto Covarrubías, and a plumber named Salvador Martínez, who assisted in disposing of the bodies. Before she could be tried, Sánchez Aguillón committed suicide by overdosing on barbiturates on June 16, 1941. ​