Authorities say Josselyn Jazmine Anguiano, 19, was going about 75 mph before she tried making a turn and lost control.
The Infiniti M37 hit a curb -- slamming into multiple poles before rolling over.
There were six people inside, all of them students at Century High School in Santa Ana.
Two teens died in the crash - her brother, 17-year-old Jason Anguiano and 17-year-old Pedro Fuentes.
The other four had critical injuries.
The crash happened around 2:50 a.m. March 23 in the 16000 block of Legacy Road.
She is facing two counts of gross vehicular manslaughter and if convicted faces up to 10 years behind bars. She has also been charged with a felony count of child endangerment by caretaker and sentencing enhancements for the injuries to the other four injured victims.