Gabriella Drozdz was hit and killed July 22 as she walked to a festival with some friends. The driver did not stop.
The family of Drozdz says the reward for information has been increased to $10,000.
Zurich police say the car that hit Drozdz may have been an older model GMC Safari or Chevrolet Astro van.
It may be blue two-tone with silver or gray.
The vehicle also may have damage to the passenger side turn signal light.
