A 15-year-old Montana girl has admitted trying to poison her father using Jell-O laced with lamp oil.

The teen appeared before District Judge Nels Swandal Monday via video conferencing. She pleaded guilty to a charge of simple assault, a lesser count than the felony attempted aggravated assault charge she first faced.

Court records say in early June, the girl made Jell-O tainted with lamp oil. Twice over a period of three days she tried to get her father to eat it. The girl and her father had recently quarreled because he revoked her privileges for missing curfew.

"What did you think was going to happen," Swandal asked the girl.

"That he'd have diarrhea and stuff," she replied.

A spokeswoman with the Rocky Mountain Poison Control Center for Montana said if lamp oil were ingested and stayed in the stomach, it would cause little trouble, but breathing fumes could cause inflammation in the lining of the lungs.

Swandal placed the girl on probation until she turns 18. Her attorney said she will enter treatment for chemical dependency.

The girl had been held at a juvenile detention center in Glendive since her arrest on June 7. Swandal did not order any more detention time.