SIRIN Phathanothai didn't know her life was special. She was raised in luxury among the founders of modern China, her presence a goodwill gift from Thailand's political elite. But it wasn't until friends suggested writing a book that she realised perhaps her life had been unusual. Even then, the first friend to suggest it was asked: ''Didn't everybody live the way I lived?'' Looking at Ms Phathanothai now, an elegant, charming, cosmopolitan woman who has devoted her life to promoting good relations between Thailand and China, that response seems almost unbelievably naive. But it was genuine. She simply did not realise how privileged she had been. In fact when she was sent at the age of eight in 1956, with her brother Warnwai, then 12, to live as the surrogate daughter of Liao Chengzhi, one of Zhou Enlai's closest advisers, and ''niece'' to the premier himself, she spent much of her time in China scheming to be sent home. ''I thought the idea of writing a book was bizarre. I thought there was nothing to write about,'' she says. It wasn't until Zhou Enlai died that she realised just how important the man she had called ''Bobo'' had been: ''At the age of eight I could not tell the difference between a great man and a normal man,'' she says. ''I was as close to him - he was like my father. I did not think of him being very special as others would see him. I took everything for granted to such as extent I only came to realise he was a great man after his death. I saw on the BBC the reports of people mourning him. It was the first time it occurred to me I had lived with a very great man. ''It was very sad in a sense, I thought, 'why did I take it so lightly?' '' Soon, the story this private woman, raised to keep secrets, found so difficult to write will be public property around the world. The US edition of The Dragon's Pearl has just been published and the UK edition is out next month. In October the Japanese version will be launched and she has just signed a contract with the Shanghai Far East Publishing House, with the publisher footing all costs instead of the usual author-pays arrangement, she says. As well, the TV and Film Literature Centre in Tianjin is looking for partners in a Thai-Chinese joint venture to make a mini-series of her life. FOR Ms Phathanothai the impact of all this exposure has not quite hit yet. The South China Morning Post interview, during a stopover here after the month she spends in China every summer, was the first on what promises to be a very long publicity trail. But already she has achieved an important and unexpected bonus from her work with co-writer James Peck: self-knowledge. ''The most important thing was understanding myself. I never knew really who I was. From a child of eight I had to live this double life in a sense. I was very close to the Chinese leaders, but I was still Thai, not like a child there with a family of her own. ''I felt an obligation imposed on me by my father. Although I rebelled against it I accepted it as the obligation of my life. I grew up with this, a sense of obligation not to lose my father's and my grandfather's face. ''But at the same time I had to make myself accepted by the Chinese society, because I loved showing off, to be one of them, to be accepted and to be loved by them.'' She had love, she had privileges. ''I had it all. My friends could not have private cars but I had a car.'' The dark side was not having her parents with her. ''But I had a sense of the importance of being there and that compensated to a certain extent.'' Then came the Cultural Revolution and, while a student at Beijing University, Ms Phathanothai's world fell apart. Her brother was sent back to Thailand, she was forced to publicly denounce both him and her father, her Japanese fiance fled and she went to the countryside, to work in a model commune in Hebei for a year-and-a-half. Back in Beijing in 1969, she worked in a factory, then sought refuge in the apartment of American friends, Sol and Pat Adler - friends who, two decades later, persuaded her to talk about her life and write it down. Rescue came from her beloved ''Bobo'' - Zhou Enlai signed a special document authorising her to travel to England with the family of David Horn, a British student she had met in Beijing. When she saw him before she left Zhou told her: ''I think it will work out. But if not, we will go back to the hills and start again.'' For Ms Phathanothai this was not merely a difficult time to write about - it was physically impossible. Although her recollection of the years with Zhou was vivid, she could not remember those three years. ''There was a blank spot. That was the difficulty in my doing anything. From the period I was in the countryside until I left for England I did not have any recollection of what happened.'' So Sol and Pat Adler's memories of her and the stories she had told them at the time form the basis of this part of her book. ''Even today that period remains unknown to me,'' she says. Ms Phathanothai married David Horn a week after arriving in England. Their marriage ended in 1978 when her father had a stroke and she moved to Bangkok. But before then they had two sons - the first, Joe, named for the premier, is now 19 and a student at Oxford. The second, Leo, is 16 and lives with his mother and her second husband, Dr Anton Smitsendonk, the Netherlands Ambassador to the OECD, in Paris, where he attends the International School. Both were with her in Hong Kong; handsome, quiet, polite young men on whose shoulders their mother has placed an obligation they have lived with so long it is part of them. That obligation was summed up for their mother by Zhou Enlai when she saw him again in August 1972: ''You have become the little bridge we once spoke about. You are both a friend and a child of China. There is much work to be done now.'' But Ms Phathanothai wasn't always so comfortable with the mission entrusted by her father: ''I had always had a certain reaction against my father, grudges against him, why did he have to do this to me?'' she says of the time she was in China. ''I wondered whether he had sacrificed his children for his political causes; this was something that remained in my mind. I think this is because I had denounced him on the radio and I knew that that was an act of shame - to denounce your father when you owe so much to him.'' But although she did not want to go and ''did all sorts of naughty things'' to get out of China (the book tells of breaking every lightbulb as she practised juggling instead of learning Chinese), she did not want her father to be disappointed in her. But gradually, as she talked to the Adlers and to James Peck, living the more stable and secure life offered by her second marriage in 1987 and Paris base, she was able to come to terms with what both she and her father had done. Until then, although she had been working to promote relations with China in Europe, much of it had been done automatically, without thinking through her life and why she felt compelled to follow this path. ''It was not the mature, thoughtful result of my experience. The book was very painful, to rethink and put all the pieces together.'' IN the acknowledgement of her book, Ms Phathanothai pays tribute to her husband, a former Ambassador to China who speaks Mandarin and understands the sense of mission his wife feels for herself and her children. Of her children she says, ''they too are bridges between worlds'' and in her dedication adds that they ''in their own way will continue the journey''. It seems a large burden for the two quiet young men who only learned the full truth of their mother's life from her book, but it's not one they find heavy. Leo, who, like his brother, speaks English, French, Thai and Mandarin and feels comfortable in Paris, Bangkok or China, says: ''It is natural, like a heritage. I am used to it, I was trained.'' Ms Phathanothai, who spent many hours during her years in Bangkok talking to her father about why he sent her to China, understands now his reasoning that Thailand had to remain China's official enemy to stay friends with the US, which it needed, but that it needed too to be friends with its large and powerful neighbour. ''He told me we have to express our resistance to the Chinese, the only way was to use the traditional custom, to send his children to that great nation.'' That great nation is today a very different place from the one the young Thai girl arrived in and from the one she fled for England. She's guarded about the changes she sees, saying she has mixed feelings but China is in a transition. Many of the old traditions were lost in the Cultural Revolution, so today people are confused, many of them grabbing at Western culture. Today the quality of China's leadership is so different - Zhou and Deng Xiaoping had trained abroad, they knew the world and their people, they had emerged from struggle. Zhou was an educated man who loved to spend time with artists and literary people: ''You don't have that level of intelligence in the leaders today and it makes a difference,'' she says.