Lisa Clark, 37, gave birth to a 7-pound, 9-ounce boy Saturday, Daniel Sammons said.
Clark has said the baby is a boy and would have the middle name of her new husband, who has not been identified by authorities because of his age. He has been identified in juvenile court only as "A.S.G."
The baby could be put in state custody unless Clark can arrange the necessary paperwork for a friend to take temporary custody, Sammons said. Clark was discharged from the hospital and returned to jail, where she is being held without bond.
"Right now, she's struggling with the trauma of having the child torn loose from her arms and possibly placed in foster care while she goes back to jail," Sammons said in a telephone interview.
Clark's teenage husband turned up in Ohio earlier this month after disappearing from a juvenile home in Georgia. It was not immediately clear where he was Monday.
Clark and the boy she is accused of molesting married in November. Georgia law allows children regardless of age to wed if there is a pregnancy.
Clark had been free on bond, but was arrested again last week after authorities said she had been communicating with her husband in violation of a condition of her release. Arraignment was set for Feb. 24. She is charged with child molestation for her relationship with the boy — her teenage son's best friend.
Authorities tracked down the boy in Ohio earlier this month by tracking a package Clark had mailed him.
Posing as a delivery man, a deputy dropped the package off at the home and was able to determine that the boy was living there, authorities said, adding that the residents did not know he was a runaway.
The package contained a cell phone and money.
Clark said in a television interview in December that the morality of their relationship was open to debate, noting that in the past it was common for 13-year-old girls to be given in marriage.
"They're making a big deal out of a 15-year-old," she told WAGA-TV in Atlanta. "And I can assure you that he was no victim.
"It's not like they are making it out to be. Actually, I'd told him 'no' several times because I prefer someone older, but he was just so nice and so sweet," she said.
Clark was arrested in November, after the couple's Nov. 8 wedding. Georgia law allows children of any age to marry — without parental consent — if the bride-to-be is pregnant. The law dates to the early 1960s and was written to discourage out-of-wedlock births.
Clark denied marrying the teen to try to avoid prosecution.
"I told the detective that I got married because I wanted the baby to have his name. I wanted to be married when the baby came," she said.