By Justin Parkinson
BBC News Online education staff
Lydia was talent-spotted by a teacher
At the age of 13, GCSEs are the last thing on most girls' minds.
Not so Lydia Hunter, who has just gained a grade B in Portuguese - despite living on the edge of a Brazilian rainforest.
The teenager, whose parents Nigel and Linda are missionary workers, was talent-spotted by a teacher at her school in the city of Petropolis, 40 miles from Rio.
She recommended Lydia be entered for an International GCSE after coming top of her class in almost every subject.
So Nigel, originally from Lisburn, County Antrim, contacted the British School in Rio.
Lydia took a test, was entered for the exam and did even better than the family had hoped.
'Better than I hoped for'
She said: "I was quite nervous. I had never been in a room full of so many people at school and I was the youngest one there.
"When the result came, on an email, I was very happy. I was hoping to pass, but I wasn't expecting to get a B."
Nigel said: "We're so proud of her. She's a lovely girl and very hard-working and considerate.
"English is her first language. We speak it at home and Lydia watches BBC World on the television."
There were two versions of the Portuguese IGCSE - one as a second language, the other as a first language. Lydia sat the latter, harder one.
Nigel said: "It was like a 13 year old in England doing an English language GCSE. She's done really well."
Lydia's school - the Espaco Verde, or Green School - is far-removed from that of most GCSE students.
It is set in a reserve area of rainforest, 2,500 metres above sea level, surrounding an old colonial building.
The nine pupils in Lydia's class start lessons at 7.30am and finish at 12.30pm, while the academic year runs from January to December.
Nigel said: "It's been a valuable experience for her. It's very different from home. The system here is normally quite old-fashioned in the way subjects are taught.
"But Lydia's schools is very down-to-earth. The teach the children to think things through. Lydia has really blossomed."
The family to Brazil eight years ago, to work with street children, and will return to Northern Ireland later this year.
In autumn 2005, Lydia is expected - like other children - to start the rest of her GCSEs.
Lydia said: "I'm really looking forward to getting back and being with my family there.
"I'm not too nervous now about doing GCSEs. I've already done one, so that should help me out."