A central Illinois woman has pleaded guilty to charges filed after an accident that left three girls dead.

Sandra M. Ross of Mattoon was charged with aggravated driving under the influence after it was determined she had marijuana in her system the morning of June 1, 2011 when she lost control of the van she was driving on Illinois Route 316 and collided with a grain truck. Killed were siblings, 15-year-old Harley Jo Madigan and 12-year-old Tanisha Madigan, and 3-year-old Keisha Person.

Coles County Circuit Judge James Glenn on Monday told the 27-year-old Ross her plea could lead to an 80-year prison sentence.

Assistant State's Attorney Rob Scales said there's no indication Ross ever had a driver's license.