Megan Stammers, who went missing a week ago with her maths teacher Jeremy Forrest, is expected to fly home to the UK today after being found in France.
The 15-year-old was found safely yesterday in Bordeaux and taken into the care of British consular staff. She later spoke to her parents on the phone.
The BBC has reported that her mother will collect her from Bordeaux and bring her back to the UK.
Forrest has been arrested on suspicion of child abduction and will remain in custody in Bordeaux until his next court appearance on Tuesday, French police sources told ITV News.
The process of having him extradited to Britain has begun.
Chief Inspector Jason Tingley of Sussex Police yesterday told reporters the breakthrough came when French police received a third reported sighting of the pair in the south-west of France.
Chief Insp Tingley said the successful outcome was a direct result of French media coverage of the case.
Megan's stepfather, Martin Stammers, told reporters he was "thrilled, delighted [and] overjoyed" to hear the successful outcome.
Megan's relatives tweeted their relief and gratitude at the good news:
Thank you everyone for everything, massive relief and thrilled to bits, more to follow later. #meganstammersfoundsafeandwell
my sisters been found!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! <3
Absolutely on top of the world of the world right now, to know our Megan is safe and sound! Love you so much my beautiful sister xxxxxx
The alarm was first raised on September 21 when Megan, from Eastbourne in East Sussex, failed to go to school. Later that evening, police discovered she had boarded a ferry from Dover to Calais with her teacher, Jeremy Forrest.
Both had tickets to return to the UK on Sunday, but did not use them.
Both Megan's and Jeremy's families made emotional appeals for their return.
Jeremy's father Jim Forrest, of Petts Wood in south-east London, begged the pair to call or email home.
On Monday, the Megan's mother Danielle Wilson and stepfather Martin Stammers also pleaded for her safe return. Danielle said: "You know that your adorable princess wants her adorable mermaid back."