Fifteen-year-old Wati showed up at a cafe in Meulaboh, a town in Aceh province, earlier this week saying that not long after the wave hit she was found and "adopted" by a woman who forced her to beg in the streets, sometimes until 1 a.m.
When she stopped bringing in money, Wati was kicked out by the woman. She then set out to find her family, but had very little information to guide her - only the name of her grandfather, Ibrahim.
Someone at the cafe tracked down a man by that name, and the man - unsure if it was actually his granddaughter - quickly summoned her parents.
"When I saw my mother, I knew it was her. I just knew it," said Wati, who was given that name by the woman who found her. Her original name is Meri Yuranda.
The Dec. 26, 2004, tsunami that killed 230,000 people in a dozen nations hit Aceh - closest to the epicenter of the magnitude-9.1 quake that spawned waves 30 feet (10 meters) high - the hardest.
With tens of thousands of bodies never recovered in the province, many people continue to cling to hope of finding lost loved ones, putting up fliers or ads in newspapers.
Reunions, however, are extremely rare and, when they occur, rarely confirmed.
Wati's mother, Yusniar binti Ibrahim Nur, 35, said she did not need a DNA test to prove the girl was hers.
"She has her father's face," she said, adding that she had stopped believing she would ever see her daughter again. "Then I saw the scar over her eye and mole on her hip, and I was even more sure."
Wati and her father had different accounts of what happened on the day of the tsunami.
The girl says she remembers her father putting her into a boat with her sister, who is still missing and presumed dead. The father says that before the family was separated, he put both of his daughters on the roof of their house.