Troopers said Melissa Patton, 32, is charged with two counts of felony driving under the influence and driving under suspension.
According to troopers, Patton was driving a car at 2:15 a.m. Wednesday on Wells Highway when the car traveled off the road, hit a church sign and overturned.
Oconee County Coroner Karl Addis said her children, 1-year-old Taniyia Chavez Leann Gambrell and 4-year-old Saryia Unique Patton-Dean, were killed in the crash.
"Both children were restrained and had to be extricated from the vehicle by first responders," said Addis. "The 1-year-old child was found in a child safety seat. She was pronounced dead at the scene."
"The 4-year-ol d was restrained by a shoulder-lap belt assembly," said Addis. "She sustained cardiac arrest at the scene."
Addis said the toddler was taken to the hospital by paramedics. She was pronounced dead at 3:13 a.m.
Both girls appeared to have died from head injuries, Addis said.
Troopers said Patton and a male passenger were taken to the hospital after the crash.
Wednesday evening family, friends and strangers gathered for a candlelight vigil at the scene of the crash.
"Saryia, she was a handful. She ran all of us. Taniyia was a happy baby. She never cried," cousin Laquasha Frasier said
"I've been seeing a lot of negativity towards the mother. She wrecked and I'm sure she didn't mean to harm her children," Frasier said.
The fathers of the young sisters told WYFF News 4 that they're not placing blame in this situation.
"I'm not blaming anyone," James Dean, father of Saryia Patton-Dean said. "I did everything I could to see her. I love my baby to death. She was my twin, she looked just like me," James Dean said.
"When it comes to family you don't never blame nobody when somebody gone. Only thing you do is put the faith in God," Terrell Gambrell, father of Taniyia Gambrell said. "The mother, that was just a mistake she made and I don't blame her -- the devil's at fault," he said.
As of Wednesday night, Patton was at the Oconee County Detention Center on a $50,652.50 bond.