A woman in Arizona is facing a charge of murder and four counts of attempted murder after allegedly poisoning her children on Christmas Day.
Connie Villa, 35, has been accused of killing her daughter and trying to poison her other three children.
She also stabbed her ex-husband at their home in Casa Grande, a small town between Phoenix and Tucson.
The police said: "Our investigation indicates Connie Villa forced her children to take prescription narcotic drugs in an attempt to kill them. Connie then contacted her ex-husband and lured him to her apartment and stabbed him repeatedly in the upper torso.
"Adam Villa was able to flee and made a 911 call to police while driving himself to the Casa Grande Regional Medical Centre."
They found the body of 13-year-old Aniarael Macias. Results of an autopsy and toxicology tests were pending but investigators believe she had been poisoned. The other three children were being looked after by their father's family and were believed to be in good condition.
Villa was arrested after she was released from hospital where she was treated for what police said were self-inflicted stab wounds. She had tried to kill the other three children, aged three, five and eight, by getting them to eat prescription narcotics, detectives added.
Tests showed that the children had trace amounts of opiates in their systems.
According to Arizona Central, a statement on behalf of Aniarael's father, Michael, who is not the father of the other children, said: "We request that the focus of this tragedy be a celebration of our precious Ania's life.
"She was a gentle, kind and beautiful spirit who was taken from us much too soon. Michael and his family are heartbroken. Ania was always smiling. She loved her brothers and sisters."