Amina Ali, who was discovered by civilian vigilantes and troops on Tuesday, flew from the Borno state capital, Maiduguri, in northeast Nigeria, to the capital, Abuja, with her mother, Binta.
Both covered their faces with headscarves as they walked into the president's office at his official Aso Rock residence, according to an AFP reporter at the scene.
They were accompanied by Borno state governor Kashim Shettima and federal government officials, including the national security advisor, defence minister and chief of defence staff.
The abduction provoked global outrage and brought worldwide attention to the conflict but until Amina's release, there were few indications of the girls' whereabouts or possible release.
Community leaders said she told her relatives at a brief reunion at the family home in Mbalala, near Chibok, that most of the girls were still being held in Boko Haram's Sambisa Forest enclave.
But the 19-year-old was quoted as saying that "six were already dead".
The abducted girls have long been thought to have been taken to the forest. Satellite imagery provided by the United States and Britain reportedly identified the location of some of the students.
But Britain's former ambassador to Nigeria, Andrew Pocock, claimed in a Sunday Times article in March that Nigeria's military failed to act on the intelligence.
Former president Goodluck Jonathan's delayed response to the abduction and overall handling of the insurgency was seen as a major factor in his election defeat to Buhari last year.