Afghan soldiers spotted the girl, known as Spozhmay, wearing a suicide jacket in southern Helmand province.
But there are conflicting reports about whether she was arrested before being able to operate the bomb or whether she handed herself in.
"My brother Zahir and his friend Jabar forced me to wear the suicide vest," she told police.
"They also gave me extra clothes to wear after crossing the water. They brought me near the river to cross at night, but when I saw the water and coldness I shouted and said that it is cold and I can't cross the water.
"They moved me back home and take off the vest from my body. My father beat me, I had to run away from home in the middle of the night and spent the rest of night in a village nearby to our home called Balochan village. And early morning I surrendered myself to the police force in that area."