Roisin O'Neill, 22, was driving a Ford Escape SUV north on southbound I-476 in Plymouth Township just before 1 a.m. Sept. 12 when it hit a Mazda head-on, authorities said.

Patricia Murphy Waggoner, 63, of Brimfield, Mass., who had been driving to Media to visit family, was pronounced dead at the scene.

O'Neill was treated at Temple University Hospital.

She is the sister of Sean O'Neill, the teen who shot and killed a friend at an unchaperoned drinking party at the O'Neills' Willistown home in August 2007. He is being held at a juvenile treatment center in Hickory Run State Park for violating probation in that case.

Her father, Sean O'Neill Sr., the former owner of a Delaware County resturant, is free on bail. Federal authorities arrested him in June, saying he lied about his membership in what authorities call a Irish terrorist organization to obtain a green card.

The charge against Roisin O'Neill will be announced at a 10 a.m. news conference, according to a news release yesterday.