No other details, such as who the babies' father is, were immediately available.
McCready made headlines Tuesday when she urged her fans not to worry about reports claiming police have described her and her 5-year-old son as "missing."
The recording artist, whose once-bright career has been overshadowed in recent years by her legal woes and drug addiction, has visitation rights with her son, Zander, but her parents have physical custody of him.
McCready reportedly picked the child up from her father's Cape Coral, Fla., house Tuesday, then took off with the boy.
A Florida judge has ordered the onetime "Celebrity Rehab" star to bring the boy home by 5 p.m. Thursday.
"My son is not missing," McCready said via Twitter late Tuesday. "Police established that this afternoon via Skype. I have been fighting the Florida court system to protect my son, and bring him home. Please do not worry."
She later told "Access Hollywood" she is "working with lawyers to try to get all this straightened out."
"I did not steal my child, as it would be impossible for me to kidnap what already belongs to me! There never was any missing persons report and never an Amber Alert," she told the TV program.