Holly Anne Alsentzer was charged Tuesday with leaving the scene of the crash and aggravated assault by motor vehicle
The accident happened at 8:55 p.m. Sunday in Southampton, Bucks County, in the westbound lanes between the Bensalem and Willow Grove interchanges.
According to police, a white Range Rover SUV lost control, rolled over the guiderail and down a steep embankment.
A 7-year-old female passenger was ejected from the vehicle and sustained serious injuries.
A 40-year-old female passenger became trapped under the car and sustained what police are described by police as "major injuries".
Both victims were taken to Abington Memorial Hospital in critical condition.
The 52-year-old male driver and 9-year-old passenger suffered minor injuries in the crash.