Misdemeanor Death By Vehicle

Earlier this year my niece (18) passed away in a car accident where the driver hit a tree. She was the only passenger in the vehicle. There has been several stories that floated around as to the cause of the accident. The driver, who was her friend, stated to the state trooper who was investigating that the steering wheel didn’t work, then the brakes didn’t work, she wasn’t speeding or doing anything reckless. Which were all proven to be false. She had told someone In confidence that she was chasing/racing two boys in a car ahead of her. This story I believe the most as the 911 caller stated that she saw two boys screaming the drivers name from the top of the hill. The police charged the driver with misdemeanor death by motor vehicle, and failure to wear seatbelt, although the black box showed that she was speeding 10 miles over speed limit she was not charged. The day after the accident the drivers family accessed the vehicle at the impound and my nieces phone is still unaccounted for. Since the accident 9 months ago the driver has received 3 speeding tickets. In NC the maximum sentence for her charge is 130 days, the police did not look into the allegation of her “racing” and did not do a further investigation other then the initial on scene investigation and the black box. No other outside agencies did a investigation either. Is there anything we can do to have the DA change her charges to something more serious? What can I do? My niece is dead and this girl is still driving recklessly and it’s looking like she will get a slap on the wrist.