Davis jumped into a sport utility vehicle with the first- and third-grade girls, and refused to leave, hoping to stop it from driving away.
"I chose to get in the vehicle," said Davis, who teaches the younger of the girls. "Those are my children 180 days out of the year. I just did what I had to do. I just had to do my job."
The SUV took off anyway, nearly hitting a school counselor, but was stopped by authorities two miles away, on Windsor Spring Road.
The pupils' mother and grandmother, who was driving, were arrested. Officials said the mother wasn't on the school's approved list to take the children and had been told so earlier in the day, when she tried to check the girls out just before school was dismissed.
The mother was identified as Naydra N. Jenkins, 39, and the grandmother as Geraldine W. Myers, 58, said school safety Chief Patrick Clayton. Both were charged with interference with schools, a misdemeanor, and booked at the Richmond County Jail, the chief said.
Clayton said the girls' father lives in the Augusta area but the mother had been staying in Alaska. Authorities said their father hadn't included their mother on the schools' approved list for pick-ups.
Hephzibah Elementary Principal Frances Ellison said she didn't know the mother's reason for wanting to check the children out. She said after being denied, the mother waited until school ended and pulled the children into the SUV.
Ellison said that's when her school's workers, who didn't know who the mother was, went into action: Davis entered the vehicle, a counselor moved in front of the SUV, and a school nurse wrote the tag number on her hand. A parent ran to a nearby police station to alert authorities, and school workers called school safety with a description of the vehicle.
"My people worked very good today," Ellison said.
Lynne Pinson is the counselor who stepped in front of the SUV.
"I backed up three times," she said. "The last time, the car touched me, and I just got out of the way."
Pinson credits Davis for protecting the pupils.
"Kristi Davis is our hero," she said. "She entered that car because she refused to let go ... and that's the kind of teacher she is."
"I will say she went above and beyond," Clayton added.
Davis, who doesn't have children, said she considers her students family.
"I'm going to protect my children just like I would want somebody to protect mine when I have them," she said.