The incident occurred on Thursday evening when an argument broke out between the teenagers on the platform of the Yerres station as a train was arriving.
The victim, an 18-year-old woman, described by prosecutor Gilles Charbonnier in stable condition, was fighting for her life, Le Parisien reported.
The woman’s legs have been amputated and she suffered from excessive bleeding and bone fractures.
She had been jostled while waiting for the train on her way home for the day, according to police reports.
Still conscious, she was treated by medics at the train station for two hours before being transported by helicopter to a regional hospital.
The suspect was interviewed after the incident and placed in detention.
The interviews were hampered by the fact the young girl was “marked by the events that resulted,” Charbonnier is quoted as saying by Le Parisien.
“She spoke sparingly.”
The two girls were placed with the same host family while attending school several years earlier and they “did not like each other,” Charbonnier said.
The 15-year-old faces a charge of attempted voluntary homicide.