It happened just before 2 p.m. Friday at Ferguson Elementary School in the 1700 block of Centerview Drive in Duluth, police said.
The school was placed on lockdown while a bomb squad investigated.
Police said they didnt find any explosives at the scene.
The mother, identified as Tamika Dena Wolterink, was taken into custody and charged with disruption of a public school and terroristic threats.
The lockdown was lifted and school was dismissed on time, said Gwinnett Count Schools spokesman Jorge Quintana.