The children are all girls, ages 3, 4 and 10.
They were in the car when Jerry William Jones, 31, critically wounded himself in the face following a high-speed police chase, the Atlanta Journal-Constitution reported.
Williams is charged with killing four people in two homes at Range, Ga., Wednesday night, including his 10-month-old daughter.
Williams was under armed guard at a hospital, and doctors said his wound was not life threatening.
Melissa Peeler, the mother of the girls, was visiting a boyfriend in Oregon when the shootings broke out. She arrived back in Georgia Friday and John Bankhead, spokesman for the Georgia Bureau of Investigation, said the girls "were very happy to see her."
Investigators say Jones' daughter was strangled, and Peeler's parents and stepsister were shot to death.