SAN ANGELO, Texas (NEXSTAR) — Authorities say a 2-month-old girl who tested positive for heroin and was placed on life support after being found unresponsive with injection marks at a West Texas home over the weekend has died.

San Angelo police said in a news release Thursday that doctors pronounced Brixlee Marie Lee dead on Tuesday at Cook Children’s Medical Center in Fort Worth.

The girl’s mother, Destiney Harbour, grandmother, Christin Bradley, and Bradley’s boyfriend, Dustin Smock, were initially charged with felony counts of causing serious bodily injury to a child. It wasn’t immediately clear if they will face additional charges; police said they are still investigating the circumstances of her death.

Officers responded to a home Saturday after receiving a report about an unconscious infant.

The girl was taken to a hospital, where injection marks were found on her extremities and head and her urine tested positive for heroin.

Investigators say the girl was apparently born in the home in August and had never received any formal medical care.

Lee’s body has been sent for an autopsy. The results are pending.

The Associated Press contributed to this report.