The school has a good academic record with 90 per cent of its students going on to university. It was also recently voted one of the 22 best state secondary schools out of 3,000 in Britain by magazine in its annual state schools guide.

But what makes Phoebe's school life more interesting is that education at Sexey's costs her parents nothing. All they pay is a boarding fee of about HK$110,000 a year - only slightly more than a secondary place at an ESF school in Hong Kong and about one third the cost of most independent boarding schools in Britain.

As an added bonus, when Phoebe finishes her A-levels this term, her time at Sexey's School will qualify her for a place at a university in England as a home student. This will mean her university fees will be about £9,000 (HK$110,000) a year, much less than those paid by her peers from schools in Hong Kong who are charged an overseas student rate.

The reason Phoebe's education is free is that Sexey's School is one of 35 state boarding schools in Britain. That means education costs are fully funded by the government.

However, there is one condition: to be able to attend a state boarding school, students must have British or European Union passports, something Phoebe holds because of the time her father spent in the UK.

Their affordability makes state boarding schools attractive among Hongkongers with relevant passports, says Sexey's headmaster Irfan Latif. Yet many are still unaware of their existence, making them "UK's best-kept secret" says Latif.

As of January this year, there were 4,897 Hong Kong students at independent secondary schools in Britain. However, a spokesman for the British Council in Hong Kong says the number attending state boarding schools is unknown.

A survey conducted last year by the State Boarding Schools' Association suggests the number of Hong Kong students enjoying a free education at state boarding schools is only a few hundred.

The survey contacted 1,500 parents of 4,300 boarders at 29 of the 35 state boarding schools. It found about 25 per cent of parents lived out of the UK, with half of these living in Hong Kong, Germany and Spain.

About 15 per cent of the 506 students at Sexey's School come from overseas. Latif says the number from Hong Kong has been rising steadily in recent years but he would like to see more young people like Phoebe become a part of their school community.

"What we gain from students like Phoebe is international perspective," he says. "Where we are is very monochromatic and rural and we think it is very important children have exposure to different cultures, whether it is a culture from Europe or China. Phoebe encapsulates everything we want in a boarder. She is approachable to [younger] pupils and her peer group. She is someone with a can-do attitude and will use her initiative to drive things forward."

State boarding schools in England are nothing new. However, in the past, says Latif, they were often viewed as a type of borstal (youth detention centre) for children the school system couldn't deal with.

"But there has been a change of image and state boarding schools have changed very much," Latif says.

"Our results are the best in Somerset and Dorset. We don't have a selective intake and for us to achieve the kind of results we do says a lot about the quality of teaching and pastoral care here. 

"And not only do we deliver on an academic front, but we deliver an all-round education. We have been in the education system for more than 100 years and we know how to bring out the best in children.

"With Phoebe we make sure she is getting involved in drama, music and sport, and that she is a mentor to younger students and taking an active role."

Phoebe's father, Edward Hung Wai-chuen, secured a British passport after studying and living in Leeds more than 30 years ago, and started thinking about sending his two daughters to study in Britain as they got older (Phoebe's younger sister also attended Sexey's but is now back in Hong Kong).

"I knew nothing about state boarding schools when we started to look for a school in the UK," Hung says. "I just wanted to widen [my daughters'] experience of life and for them to be more disciplined and I hoped they would cope with boarding life. That is the reason we applied for boarding school.

"After a year I tried to find a private school but Phoebe said she didn't want to change. She had settled in and made good friends at Sexey's. Both daughters loved it and wanted to be there."

Phoebe, now 18, admits it was difficult being away from home at first, but the interview had helped ease some worries.

"Our whole family came over in May for the interview," she says. "As we walked around the school I remember thinking this is the school I am looking for. Everyone was smiling at us and saying "ni hao".

"When I moved here I was quite nervous and it was difficult being away from home, but in less than a week I was getting on really well with my friends."

This month Phoebe will sit three A-levels. In the future, she is considering studying physiotherapy either at university in Britain or Hong Kong. She says she will never forget her school days at Sexey's.

"I have only got a few months left now and I really don't want to go," she says. "I have made friends from all over the world and my advice to anyone considering coming here would be 'go for it'."