Melissa Jean Day of Ramona died around 2:40 p.m. Sunday just north of Poway Road, according to the California Highway Patrol and the San Diego County Medical Examiner's Office.
Day was driving south with her daughters in her 1994 Ford Ranger when a northbound 2002 Ford Ranger struck a curb and veered into her path, San Diego County sheriff's Lt. Lloyd Muenzer said.
Day's daughters, 11 and 14, were airlifted to Children's Hospital for injuries ranging from a possible broken arm to lacerations, according to Muenzer.
The other driver, a 17-year-old Ramona boy, and his 15-year-old female passenger were taken by ground ambulance to Palomar Medical Center in Escondido. Their injuries were not believed to be life-threatening.