According to the sheriff's office, it happened June 26 just before 4 p.m.
Arlene Mary Bonitz, 57, of Palm Harbor, Florida, was driving south on I-95 near the 64-mile marker in Godwin with a man with cognitive impairments for whom she is a caregiver.
Sheriff Ennis Wright said Bonitz apparently stabbed the man several times with a Sharpie marker and then pushed him out of her car while driving 60 mph. She then drove on for several miles on I-95 until she was involved in a single-vehicle crash.
The Highway Patrol responded to the crash.
Both the victim and Bonitz were taken to a medical center for treatment.
The man suffered a broken pelvis and had road rash on his face, hands, and legs.
Detectives arrested Bonitz on Friday, and she was charged with assault with a deadly weapon with intent to kill.
She was given a $75,000 secured bond, and her first court appearance was Tuesday afternoon at the Cumberland County Detention Center.