Yesterday, prosecutors charged the 22-year-old with homicide by vehicle, driving under the influence of alcohol, and related offenses in the Sept. 19 crash that killed Patricia Murphy Waggoner of Brimfield, Mass.

O'Neill "endangered the lives of many that night," Montgomery County District Attorney Risa Vetri Ferman said.

O'Neill also became the third member of her family to face criminal charges in the last 26 months.

The Newtown Square resident arrived at yesterday's hearing by transit ambulance and in a wheelchair. A blanket covered an ankle shattered in the crash. Her hair, streaked with red highlights and uncombed, was pinned up above the neck brace she wore. Throughout the hearing, she sobbed, wiped her eyes and nose, and covered her eyes.

Her parents - Sean Owen O'Neill Sr. and Eileen O'Neill - accompanied their daughter and posted the required 10 percent of the $25,000 bail. District Judge Deborah A. Lukens told Roisin O'Neill that she was forbidden to drive, and could leave home only for medical appointments and Sunday religious services. O'Neill was asked to surrender her driver's license and passport.

Her attorney, Vincent P. DiFabio, said his client "most likely" would plead guilty.

"I know the O'Neill family is devastated by the tragedy," DiFabio said.

Sean O'Neill Sr. is also out on bail. He was arrested in June after authorities alleged he lied about his membership in what they are calling an Irish terrorist organization to obtain a green card. He formerly owned Maggie O'Neill's pub in Drexel Hill. The pub was sold in 2007.

His son, Sean O'Neill Jr., is being held at a juvenile detention center for a probation violation. In August 2006, the younger O'Neill shot and killed a long-time friend during an unchaperoned drinking party at the family's home in Willistown Township, Chester County.

"To face every day is just hard right now," Sean O'Neill Sr. said. "Our hearts and souls go out to the Waggoner family, and they are in our prayers constantly."

According to the affidavit, Roisin O'Neill met friends just after 10 p.m. on Sept. 18 at Brownies 23 East on East Lancaster Avenue. She later admitted to police that she had two whiskey drinks before she arrived at the bar and a "beer or two" after she arrived. Video surveillance shows that O'Neill "exited the bar's rear door at 11:34 p.m. to smoke and then reentered the bar through the same door," the affidavit said.

Brownies employee Paul R. Nangle was working security at the front door. He told police that he refused to let O'Neill back in when she left a few minutes after midnight.

Nangle said that he asked O'Neill if she was driving and that she said she wasn't. He offered to call a cab for her, and she refused.

Ferman said O'Neill has no memory of how she got to Matsonford Road and DeHaven Street in Conshohocken, where she entered I-476. Police said she passed two "Do Not Enter" signs, two "Wrong Way" signs and two "One Way" signs going up the exit ramp. Police said they interviewed five drivers who swerved to get out of her way as she drove, flashing her high beams, at high speed in the wrong direction for more than three miles.

Seconds before the collision, Waggoner also attempted to get out of the way of the speeding Ford Escape. She swerved her Mazda right just as O'Neill swerved left and head-on into the smaller car.

Waggoner died on impact of "cerebral trauma and chest trauma," according to the coroner's report.

Roisin O'Neill was flown to Temple University Hospital. Her blood alcohol level registered 0.197 - more than twice the legal definition of drunen driving. There were traces of marijuana found, authorities said.

Waggoner was on her way to her son's home in Media to celebrate a granddaughter's sixth birthday and to attend a Grandparents Day at the school of a younger granddaughter, police said.

Roisin O'Neill's "life will be changed forever because of her actions," Ferman said. On just the homicide-by-vehicle charge, O'Neill faces a minimum of three years in prison.