At the ripe, old age of 12, almost running someone down sounds like total lack of skill behind the wheel and probable absence of malice. If she really had the skill required to run the cop down and the malicious intent to do it, she'd have been able to keep him lined up with the hood ornament in spite of all his dancing around and he wouldn't have had a prayer.
The article relates that after the officers pinned the car with their police cars, and got out to make the arrest (or investigation...), the car lurched forward and BACKWARD, breaking loose from the pin and heading for the officer.
The ramming and backing to ram again or break free is a fully intentional act, as well as being a highly dangerous one. The officer found himself in the path of an escaping vehicle being driven by a desperate driver with no regard for lives or property, just escape from the police.
Given that the officer couldn't see who was driving, there were no constraints on his duty to protect his own life by shooting. Even if he had seen that the driver was a small person, he certainly couldn't have determined how old the driver was in that split life-or-death second.
Young offenders are often highly dangerous to law enforcement, because they do not have the common sense or experience to know how to rationally react to a stressful situation. Kids with real guns often shoot first, just like on TV, or like this girl, turn a car into a deadly weapon when the cops come to arrest, cite, etc.
No policeman can predict how anyone will act in those circumstances, which is why they treat everyone with suspicion. Kids are the worst.