its not accidental. its negligent.
accidental, would be if she had good tires on her can and one blew out, sending her carreening into the other driver.

negligent is not being in charge of your car. allowing people to be unbuckled. leting someone crawl through the vehicle while traveling at highway speeds. (and if she was talking on the phone, texting whatever else) we will call it MURDER. well maybe not but close. i hope they hang her.