An Associated Press reporter saw the 14-year-old in a hospital in Comoros when the country's vice president visited her Wednesday. A nurse who treated the girl said she was "doing well."
The girl's father told French radio that his daughter could barely swim but managed to hang on long enough for rescuers to find her in the Indian Ocean.
A Yemenia Airbus 310 jet carrying 153 people crashed into the Indian Ocean early Tuesday as it attempted to land in the dark amid howling winds.
France's transport minister says one of the black boxes has already been found, but there is no word on other survivors.
Kassim Bakari said he spoke with his oldest daughter, 14-year-old Baya, by phone after Tuesday's crash. Baya had left Paris on Monday night with her mother to see family in the Comoros.
"(Baya was) ejected, she found herself beside the plane," her father said, describing her as "fragile" and saying she could "barely swim."
"She's a very timid girl, I never thought she would escape like that," Bakari told France's RTL radio.
Said Mohammed, a nurse at El Mararouf hospital in the Comoros capital of Moroni, said the girl was doing well and doctors would release more on her condition later Wednesday.
Sgt. Said Abdilai told Europe 1 radio that he rescued the girl after she was found bobbing in the water. She couldn't grasp the life ring rescuers threw to her, so he jumped into the sea, Abdilai said. He said rescuers gave the trembling girl warm water with sugar.
The crash a few miles off this island nation came two years after aviation officials reported equipment faults with the plane, an aging Airbus 310 flying the last leg of a Yemenia airlines flight from Paris and Marseille to the Comoros, with a stop in Yemen to change planes.
Most of the passengers were from the Comoros, a former French colony. Sixty-six on board were French nationals.
Turbulence was believed to be a factor in the crash, Yemen's embassy in Washington said.
The tragedy - and dwindling hopes that anyone else made it out alive - prompted an outcry in Comoros, where residents have long complained of a lack of seat belts on Yemenia flights and planes so overcrowded that passengers had to stand in the aisles.
Gen. Bruno de Bourdoncle de Saint-Salvy, the senior commander for French forces in the southern Indian Ocean, said the Airbus 310 crashed in deep waters about nine miles north of the Comoran coast and 21 miles from the Moroni airport. Searchers encountered an oil slick at the site, the Yemeni Embassy statement said.
French aviation inspectors found a "number of faults" in the plane's equipment during a 2007 inspection, French Transport Minister Dominique Bussereau said.
European Union Transport Commissioner Antonio Tajani said the airline had previously met EU safety checks and was not on the bloc's blacklist. But he said a full investigation was now being started amid questions why passengers were put on another jet in the Yemeni capital of San'a.
An Airbus statement said the plane that crashed went into service 19 years ago, in 1990, and had accumulated 51,900 flight hours. It has been operated by Yemenia since 1999. Airbus was sending a team of specialists to the Comoros to help in the investigation.