A member of the Concerned Relatives of Abducted Persons, Sani Musa confirmed the development to Channels Television on Sunday.
The pregnant woman was said to have been released on compassionate ground on Saturday afternoon after she and 61 others had spent 45 days in captivity.
Shortly after her release, Thamina Mahmood was seen in a viral video, where she appealed to the Federal Government to negotiate with the terrorists.
She also said that the terrorists took care of them including feeding and their medical needs while in captivity, however, she noted that such treatment cannot be qualified with the comfort they would have enjoyed if they were in their various homes.
A young woman, Dr. Chinelo Megafu Nwando, was one of those who lost their lives in the dastardly attack.
She died from injuries sustained from gunshots when the Abuja-Kaduna bound train she was travelling in was attacked by terrorists in the Kateri-Rijana area of Kaduna State in March.