The jihadist terror group Boko Haram continued to hold a Christian schoolgirl captive after 85 days for refusing to renounce her faith and convert to Islam after she turned 15 this week.

Leah Sharibu, one of the 110 girls Boko Haram kidnapped from their school in northeast Nigeria’s Dapchi region on February 19, recently turned 15 while in captivity.

Boko Haram has released all Dapchi girls except for Leah.

Nigeria’s Premium Times reported this week, “The kidnapped teenage student, Leah Sharibu, will on Monday mark her 15th birthday in the custody of her captors. Miss Sharibu is the only one of the schoolgirls kidnapped from Dapchi still with the terror group, Boko Haram.”

Citing her schoolmates, her parents, Nathan and Rebecca Sharibu, told USA Today in March that the terrorists will not release her until she converts to Islam.

“My daughter is alive, but they wouldn’t release her because she is a Christian. They told her they would release her if she converted, but she said she will never become a Muslim. I am very sad, but I am also overjoyed because my daughter did not denounce Christ,” Nathan told the newspaper.

Rebecca recently told CNN that Boko Haram “said she should turn to Muslim before” they can let her go “and then she said she would never do that.”

“When my daughter comes back, I will not allow her to go to that school again,” she added.

Boko Haram is known for kidnapping children, particularly girls.

In April, the United Nations revealed that Nigeria-based Boko Haram has abducted more than 1,000 children in the northeastern part of the African country since 2013 alone.

The Nigerian government released grim fatality data linked to the terrorist group early this month.

Jihadists from Boko Haram, a name that translates to “Western education is a sin,” have killed 100,000 people since the group began waging its insurgency in 2009, including 2,295 teachers and hundreds of students in the northeastern part of the country alone, according to the Nigerian government.

Northeastern Nigeria’s Borno state is considered Boko Haram’s birthplace.

“In April, the Nigerian government said a disagreement between members of Boko Haram had caused a breakdown in negotiation talks for the release of remaining schoolgirls in the group’s captivity,” CNN noted.

On several occasions, including while Leah has been captive, the Nigerian government falsely claimed to have defeated Boko Haram.

The Nigerian Army reportedly claimed it expects to annihilate the group by the end of August.