The crash happened at about 5:30 p.m. when driver of the 1990 Honda sedan was attempting to turn from westbound Gravenstein Highway onto southbound Madrone Avenue, and turned directly into the path of an eastbound 1973 Chevrolet pickup, Sgt. Steven Burns said.
The driver of the pickup, Mark Ackerman, 55, of Cotati, was unable to avoid the collision and struck the passenger side of the Honda, Burns said.
The Honda's driver, Luz Mejia, 20, of Petaluma, was not injured, police said.
The girl was still inside the Honda when paramedics arrived. She was stabilized before she was removed from the vehicle, and was then taken to Santa Rosa Memorial Hospital where she was in critical condition Monday, Burns said.