Ruby's mother, Renee Gould, was transported to UCI Medical Center for a dislocated shoulder and fractured vertebrae.
A third child, Jacob Chuntz, was not injured. Ruby and Renee Gould, from Australia, were visiting family in Orange County.
On Sept. 12, the family amended its lawsuit to include new evidence, according to their attorney, Marcus Bradley.
According to the lawsuit, the city created a false sense of security for pedestrians crossing the street shortly before the crash when it disabled overhead lights and instead placed lights in front of the crosswalk, making it seem like the lights were flashing when they were not.
"If these overhead flashing signs were illuminated, Casares would've realized that there were pedestrians crossing the street," Bradley said.
On Sept. 16, Johnson filed a lawsuit against Casares for causing the accident and the city for neglecting a dangerous crosswalk.
Her lawsuit asserts that she suffered injuries that have left her with permanent disabilities, emotional scars, shock and distress and that she continues to seek medical help.
Her husband, Ronald Johnson, also claims a loss of consortium.
The two lawsuits have been combined in court, Bradley said.
City Attorney Jennifer McGrath would not comment on either lawsuit because they involve pending litigation.
The Goulds and Chuntzes' lawsuit also names Casares and Johnson and alleges negligence, dangerous conditions of public property, wrongful death and emotional distress.
Casares pleaded guilty to one misdemeanor count of vehicular manslaughter and was sentenced in March to three years of informal probation, 300 hours of community service as a school crossing guard and ordered to pay $5,500 to the Joyful Child Foundation.