A mother was charged with a felony after her one-year-old daughter died from fentanyl.

Charlotte Chavez, 31, appeared in court on Sept. 2 after prosecutors in the Denver District Attorney’s Office’s Family Violence Unit charged her with one count of child abuse resulting in death – a felony, according to a Wednesday press release.

Last December, Chavez called 911 to report that her daughter Betty wasn’t breathing. Paramedics brought the baby to Denver Health Medical Center, but she died.

An autopsy by the Denver Morgue found that “Betty died as a result of the toxic effects of fentanyl.” It also detected naloxone – a medicine that reverses opioid overdoses – and acetaminophen in her body. Acetaminophen is a pain reliever, with Tylenol recognized as a common brand.

In July, Chavez waived her right to having an attorney present during an interview with a Denver police detective and gave a statement.