She was a barefoot waif, gazing solemnly into a camera with huge brown eyes. This was my first sight of Wiwit, the child I began sponsoring through Plan UK back in 2002.

Wiwit was aged six then, and the photograph of her was one of two I received from Indonesia, where she and her family live in a remote village on the island of Java.

The other photo showed Wiwit with her mother, Sutinah – who was also barefoot, and also looked very solemn.

An accompanying letter of introduction from a community volunteer called Dasiman explained: "Don't worry about the serious expressions on their faces.

"A photo is a very serious thing here – the villagers have no culture of taking pictures for fun.

"On the very few occasions their photo is taken, they make a real effort to express their dignity."

The letter went on to tell me that Wiwit's mother and her father, Martoyo, were both peasant farmers, and that the family lived in a small wooden house with a slate roof, with no lavatory. Wiwit also had a younger sister, Rosi, then aged two.

As I read about how the family had to get their water from nearby rivers and streams, and boil it for at least 10 minutes, something that I'd done on a whim suddenly started to feel very real.

I'd decided to sponsor a child through Plan UK on impulse, after my two boys – then aged four and two – announced that they wanted a little sister.

The mother of one of their friends had just had a baby girl, and the boys had decided they wanted one too. They didn't understand they might end up with another brother – or comprehend my reluctance to go back to nights without sleep and days changing nappies.

Then I came up with the solution that brought Wiwit into our lives.

A few days earlier, I'd seen a newspaper advert about sponsoring a child through Plan UK, which is part of a global organisation with development programmes in 45 of the world's poorest countries.

I'd seen some of the problems faced in such countries for myself, when my husband was South-East Asia correspondent for a national newspaper.

We lived in Thailand, in a house in Bangkok that we had inherited from the previous correspondent.

Rather grandly, the house came with its own maid – a tiny, smiling woman called Kiaow – who lived with her husband in a separate apartment.

It was only after we'd lived in the house for a few months I realised that Kiaow and her husband had two daughters, who lived with relatives in their home village in northern Thailand, near the border with Laos.

The girls would come to stay in the school holidays, but it was accepted that they had to stay in the village while their parents worked in the city because there was little work available in their rural community.

I came to realise that this rural migration was not unique to Thailand, it was also commonplace in neighbouring countries such as Cambodia, Burma, and Malaysia.

In fact, Kiaow was in many ways one of the lucky ones.

Although she did not see her children often, she had a job – unlike many of those who came to the cities looking for work – and at least she had not become involved in the sex industry like many uneducated girls from rural areas.

Sadly, when we left Thailand we lost touch with Kiaow and her husband, but I often wonder about them and their daughters.

They were on my mind when I read the advert about the work of Plan UK.

At £12 a month, it seemed pretty good value.

I probably spend that much some weeks on cups of coffee – and I told my boys that instead of getting a baby sister we were going to sponsor a little girl from another country.

Over the years that have followed since I received those first photos and the letter about Wiwit and her family, there has been more correspondence. In the early days, Wiwit could not write, and I would receive letters from her mother and her father. Then Wiwit started writing herself, in small, neat handwriting, telling me about celebrations such as the Idul Fitiri feast following a month of fasting, and about how she had begun elementary school.

There were also photos of Wiwit and her family.

It has been a real delight to see that barefoot waif blossom into a lovely young girl, who is able to attend school and looks so smart and confident in her uniform.

I also get regular updates about the region from Plan UK.

The latest one has been about how families such as Wiwit's in rural areas of Indonesia are being helped to increase their incomes through projects which provide business skills and vocational training, and give advice and loans for setting up small businesses.

Sometimes I wonder what the future will hold for Wiwit.

In moments of aspiration, I envisage her doing well at school, and going on to enjoy a successful career that will help take her and her family away from the poverty of peasant farming.

Usually, however, I think that at least Wiwit and her family now have clean water, proper latrines and electricity in their village thanks to the work of Plan UK.

Whatever happens to Wiwit, I like to think that her life now is better than when that first photo was taken back in 2002, and that my £12 a month has helped to play a part.