Sherrie Orndorff, the mother of the victim who survived the crash, says her 11-year-old daughter Natalie lost her leg in the collision. She's had surgery on both arms and is on dialysis because her kidneys aren't functioning.
"She's very much in pain, and uncomfortable and confused," the mother says.
Orndorff says her daughter still doesn't even know the other three girls were killed.
"She's still having problems with her memory, she remembers nothing about the accident, she hasn't asked nothing about her friends yet," Orndorff says.
RELATED: 3 girls killed, another critically injured after hit-and-run crash in Lucerne Valley
Orndorff is urging the people responsible to turn themselves in after the driver and a passenger fled the scene of the crash.
"I'm appealing to them and their sense of conscience right now. I know... you must feel horrible," Orndorff says. "I don't know how you can live with yourself or sleep at night. I barely can. You know who it is, or it's you, you can just come forward."
The California Highway Patrol says the crash happened June 5 along Camp Rock Road. Natalie, along with friends Willow Sanchez, 11, Daytona Bronas, 12, and Sandra Mizer, 13, were walking down the street around 10:20 p.m.
Orndorff says she feels horrible about what happened because she was the one supervising the kids.
"It was Saturday night, summertime, it had been 110 that day," Orndorff says. "It had just cooled off. I said, 'OK, right here out on the property.'"
But the girls wandered off down the street and were then struck from behind by someone driving a white Chevy Silverado. Both the driver and passenger fled the scene.
The Highway Patrol has the vehicle and says the registered owner is cooperating, but they haven't released any information on potential suspects.
CHP says they do know things they can't release because of the investigation.
"It's just frustrating as a parent, you want to know now," Orndorff says.
A GoFundMe page has been set up for the families of the victims.