Teenage student Yashika Bageerathi has said she is “very frightened” after landing in Mauritius following her deportation from the UK.
The 19-year-old spoke to the headteacher at the school she attended in north London after she was interviewed by police at the airport.
She is now believed to be looking for somewhere safe to stay in her home country.
Ms Bageerathi’s removal from Britain went ahead after a last-ditch attempt to secure an emergency injunction failed on Wednesday evening.
She was put on an Air Mauritius flight at Heathrow, despite more than 175,000 people signing up to a petition calling for the government to halt the deportation.
Lynne Dawes, headteacher at Oasis Academy Hadley in Enfield, north London, said the school was keeping in contact with the A-level student and that the immediate concern was to find her a safe place to stay.
Ms Dawes said the student was feeling “low” and said: “She’s feeling the lowest I have heard her be for quite a while. She was also very subdued.”
She confirmed four security guards had accompanied Ms Bageerathi on the flight.
The headteacher also said the school was still working to ensure she would be able to complete her A-levels.
Ms Bageerathi had been trying to claim asylum after arriving in the UK with her mother, sister and brother in 2011, saying that a relative had been physically abusive.
She had been held alone at Yarl’s Wood immigration detention centre in Bedfordshire since March 19 and had already had two late reprieves from deportation after airlines apparently refused to fly her home.
A spokesman for the Oasis charity, which runs the academy, said they were supporting the family, as well as the student, who he described as “very frightened”.
Immigration Minister James Brokenshire told MPs earlier this week that he would intervene only in “exceptional” cases, and this did not fall into that category.
He said Ms Bageerathi’s case had been through the proper legal process and resulted in a Home Office decision that she does not need protection from violence or persecution.
The rest of her family are still in Britain, although her mother is due to be deported at a later date.