The president had promised to intensify efforts to secure the release of the remaining girls and other abducted persons, as well as bring an end to the 8-year Boko Haram insurgency that has killed over 30,000 people and displaced millions.
It was Mr Mustapha who succeeded in convincing the Nigerian authorities that this particular group should be taken for what they say, presidential spokesman Garba Shehu told me.
Femi Adesina, the president's adviser on media, told the BBC broadcaster the girl came across government troops after escaping Boko Haram, an Islamist group active in the region.
82 Chibok girls who were released by the Boko Haram militants.
Of the 270 girls originally kidnapped, around 60 have escaped and more than 100 have been released.
"The girls released in October a year ago are still in government custody which is very disturbing", said Isa Sanusi, spokesperson of Amnesty International in Nigeria.
The process of asking each of the girls whether they were molested was also repeated when 82 more were released earlier this month.More news: Internet claims Avril Lavigne has died and been replaced
More news: Fox Cancels Scream Queens
More news: Coroner: Teen had healthy heart before caffeine
In total, 164 girls have regained freedom while 112 of them are still in captivity. She wonders why "the families who have been longing for them" have had so few opportunities to see them.
The release was made possible by the assistance of the International Red Cross as "neutral intermediaries" and the Swiss government.
Diane Cole writes for many publications, including The Wall Street Journal and The Jewish Week, and is book columnist for The Psychotherapy Networker. She is the author of the memoir After Great Pain: A New Life Emerges. "Because of Margaret and Asabe, that is why she developed sickness", he said. He said his niece has told him that "only females can sneak in to see them sometimes but males are not allowed into the compound".
"While Boko Haram may indeed hold out in releasing all of the hostages to maintain some form of leverage, the reality is that the girls have limited value to the sect outside of public relations capital and are likely placing a strain on resources", he said.
One of about seven Boko Haram militants, who accompanied them, went from woman to woman asking: "Throughout the time you were with us, did anyone rape you or touch you?"
It added that the girls would be given appropriate and comprehensive medical and psychological care and support, and government would underwrite all of the care they will receive, as well as ensuring that their education is concluded. "We want them to accept Islam", she said, as reported by Al Jazeera. "They all live in different villages that are far apart so we can't reach all of them immediately".