Serah Luka, who was rescued Thursday, did attend the school, but wasn't abducted at the same time as the 276 taken from the school on April 14, 2014, according to Bukky Shonibare of the #BringBackOurGirls campaign.
"However, the same way we rejoice over the return of the Chibok girl, so also is our joy over this one," Shonibare said.
A Nigerian army officer said Thursday that Luka was part of the mass abduction. On Friday, Army Brig. General Abubakar Rabe declined to address whether Luka was part of that abduction.
"We shouldn't focus on whether she is one of the Chibok girls or not," Rabe said. "The important thing is that we are pursuing Boko Haram and rescuing human beings on a daily basis. We should be allowed to be concentrate on rescuing other people in our operations."
The girl was one of 97 women and children were freed during Thursday's operation, according to Col. Sani Usman. At least 35 Boko Haram fighters were killed.
Initially Usman said Luka -- the daughter of a pastor -- had started at the boarding school in Chibok a little more than two months before the Boko Haram raid.
Activists and residents of Chibok disputed the claim and asked for more verification, saying Luka's name was not on the list of those missing.
Thursday's news came the same day another kidnap victim, Amina Ali Nkeki, met with Nigerian President Muhammadu Buhari at the presidential villa in Abuja on Thursday.
She had been found two days before in northeastern Nigeria after apparently escaping from the terror group.
During the emotional meeting, Buhari held the baby Amina gave birth to while a captive of the terror group.
"Like all Nigerians and many others around the world, I am delighted that Amina Ali is free, but it is tinged with deep sorrow with what she had to go through," Buhari said.
Amina was accompanied by her family and Borno State Gov. Kashim Shettima, whose residence she had visited the previous night.
Shettima had treated Amina, who was limping and severely malnourished when she arrived with her baby at his home, like a "VIP guest," a state government official told CNN.
"She is receiving high-level medical attention and the best doctors in the state are attending to her. The governor ordered for her release from the military as he wanted to make sure she and her baby daughter received urgent medical and psychological attention," he said.
Separated from 'husband'
Amina was the first of the so-called Chibok girls to escape since the 276 schoolgirls were kidnapped at gunpoint from their boarding school in northeast Nigeria.
As many as 57 girls were able to escape almost immediately, but more than 200 have remained missing since then.
When Amina escaped, she was accompanied by a young man who said he was her husband and the father of her baby. He said he had been kidnapped by Boko Haram and taken to their forest stronghold, where he married Amina.
But a government official told CNN that Amina had been "completely detached" from the man, who remains in military detention and is being interrogated.
Amina was briefly reunited with her mother on Tuesday night at the family home in Mbalala before being held by the army, CNN learned.
A neighbor who witnessed the emotional meeting told CNN that her mother, Binta Ali, was very distressed when she first saw her daughter.
"The mom was very disturbed," said the neighbor, who did not want to be named.
"She was full of happiness but at the same time seeing the situation of her daughter, who is a Christian, with a baby and a Boko Haram husband and wearing a hijab, she was just crying bitterly," said the neighbor.
"Even Amina was comforting her mother saying she should be happy to see her alive. She was very happy to see her but she was also very sad."
It is still unclear how Amina escaped from the clutches of Boko Haram, but the government official said it was likely as a result of the sustained military campaign in the Sambisa Forest. The dense forest in Nigeria's northeast is believed to be the terrorist group's stronghold, and has long been the suspected location of the missing girls.
"The governor has ordered that no one should ask her any questions for now but it's likely that she may have taken her chance to escape based on a military attack carried out in the Sambisa Forest," the official said. "I believe more Chibok girls could have escaped and could still be in the Sambisa."
On Wednesday, a member of a civilian vigilante group set up to help fight Boko Haram told CNN he had been on a nightly patrol on the edge of Sambisa Forest on Tuesday night when when the girl and some companions wandered out around 7 p.m.
He recognized her as one of the missing schoolgirls, although she looked different and was in poor physical condition, as were the baby and man with her.
Nigeria's government has said the girl was rescued by government troops that were working with the civilian force. Operations to find the missing girls have intensified recently with a deep push into Sambisa Forest, a military spokesman told CNN's Nima Elbagir.
Campaign of terror
The girls' kidnapping sparked global outrage, including the #BringBackOurGirls campaign on social media.
But Nigeria's government has so far proven largely powerless to recover the girls.
Last month, CNN obtained a video of some of the missing Chibok girls that had been sent to negotiators by their captors as "proof of life," and showed it to some of the girls' mothers, who had not been shown the footage by officials.
Boko Haram, based mainly in Nigeria's northern states but responsible also for attacks in neighboring countries, is seeking to implement sharia law. According to a report released in November, the Global Terrorism Index, Boko Haram was the world's deadliest terrorist group in 2014, responsible for 6,644 deaths, compared with ISIS, which was responsible for 6,073.
Besides the spate of kidnappings, the group has also pursued a ruthless campaign of bombing marketplaces throughout Nigeria and neighboring countries.