BILLINGS, Mont. — A Montana woman accused of killing a 13-month-old girl she was caring for and putting the child’s body in a dumpster has pleaded not guilty to federal murder charges that could put her in prison for the rest of her life.

Janelle Red Dog, 42, of Poplar has been charged in the killing of Kenzley Olson on the Fort Peck Indian Reservation in April.

She entered the pleas Thursday to first-degree murder under the felony murder rule, second-degree murder and felony child abuse.

Red Dog also pleaded not guilty to being an accessory after the fact. Authorities said she covered up aggravated sexual abuse.

Another suspect was not named and was listed as John Doe in an indictment filed in U.S. District Court. No details about the sex abuse allegation, including the victim’s name, were disclosed in court documents.

Federal public defender R. Hank Branom said he did not know any details about the abuse allegation beyond what was in the indictment.

Assistant U.S. Attorney Melissa Hornbein said the identity of John Doe was unknown. She declined comment on any possible link between the sex abuse allegation and Kenzley’s death.

Fort Peck tribal leaders have linked Kenzley’s death and the recent kidnapping of a 4-year-old girl in Wolf Point to a methamphetamine epidemic on the northeastern Montana reservation.

A first-degree murder conviction would be punishable with a mandatory life sentence and no possibility of parole.

Red Dog was placed in federal custody following Thursday’s hearing before U.S. District Judge Brian Morris in Great Falls. A trial was scheduled for Nov. 21.

Red Dog reported on April 19 that Kenzley had been abducted, prompting an Amber Alert and a search in Montana and neighboring North Dakota.

Authorities said they canceled the alert after Red Dog drew a map that led them to the baby’s body inside a duffel bag in a dumpster several blocks from Red Dog’s house.

Investigators said Red Dog acknowledged striking Kenzley, who died of blunt force trauma.

Kenzley had been under Red Dog’s care for about two weeks before she was killed, after her mother dropped her off and failed to return, according to Red Dog’s mother and the lawyer representing her on related charges filed in Fort Peck Tribal Court.

The defendant’s mother, Rhea Starr, said she believes Kenzley’s death was an accident. Red Dog was caring for Kenzley because no one else would and the girl had been sick with a fever in the days before her death, Starr said.

“My daughter would not intentionally ever hurt a child,” Starr said.

Red Dog was initially charged in tribal court with murder and a misdemeanor count of hindering law enforcement. Those charges are pending.

The tribal law murder charge has a maximum penalty of three years in prison.