Haillie Shimmel is in good condition at Children's Hospital in Oakland, hospital spokeswoman Erin Goldsmith said.
The girl's father, John Shimmel, of Santa Rosa, released a statement through the hospital.
"Haillie is doing well and healing in the hospital. She is out of a medically induced coma and recovering amazingly quickly. The Shimmel family appreciates everyone's concern and prayers," Shimmel said.
Shelli Shimmel, 43, of Santa Rosa, was killed when the 2004 Chevrolet Trail Blazer she was riding in, driven by 18-year-old Sebastian Hollingworth of Santa Rosa, crashed on southbound Petaluma Hill Road in unincorporated Sonoma County the evening of Oct. 8.
The SUV drifted into the northbound lane and Hollingworth lost control when he steered hard to the right, CHP officials said. The Chevrolet left the road, struck two trees, rolled onto its roof and landed in a drainage ditch.
The CHP later said that Hollingworth had been distracted because he was looking down at money in his lap.
Haillie's sisters, Sherilyn Hollingworth, 16, and Shayne Hollingworth, 13, of Santa Rosa, were treated at Santa Rosa Memorial Hospital for their injuries, according to the CHP. Sebastian Hollingworth suffered minor injuries.
The CHP said alcohol is not considered a factor in the crash. A trust fund has been set up at the Redwood Credit Union in the memory of Shelli Shimmel to benefit her children.