But the trip changed everything. After the dream wedding, they decided to have a working holiday doing something to help others. On arrival in Durban, they were driven 30 miles to the Makaputu Children's Village, an orphanage which was home to a few of the estimated 3.4 million children who had been orphaned by AIDS in South Africa.

They spent their stay caring for and playing with children who had either been orphaned by parents dying of AIDS or by the death of parents whose neighbours had shot them on learning that they had the disease, sometimes in front of their children. Some of the children had a parent, both parents or other family members still, but the family could not accept the fact that the youngster had HIV.

A small, overworked staff and a few volunteers ran the orphanage, which was surrounded by razor wire, not only to stop youngsters from running away but to prevent intruders from kidnapping and abusing the children.

The newlyweds visited other projects in the area, including a hospital ward for adults with AIDS and a playgroup, and on their last day they were allowed to take a few children to the beach. Frolicking in the waves and licking ice-creams were experiences Natalie's own children took for granted, but for these little ones such treats were unknown.

"We both knew the trip would be life-changing, but I don't think we couldn't know beforehand just how much it would change us," says Natalie, who lives with her family in East Yorkshire.

"We saw some children with HIV who were horribly ill because of a lack of basic medical care like antibiotics. While we were there I went and bought a big bottle of antibiotic syrup to help, but the staff were too scared to use it because when it ran out there would be no more. Meanwhile children were becoming needlessly very ill with ear infections and tonsilitis. It was heart-rending."

On that final day at the beach, one of the children in the group was a sick 20-month-old called S'bahle (Star). "She never smiled at us, hated cuddles and smelled pretty awful, with mites in her hair and infected pustules on her scalp. I was taking a photo of her with Ian when she looked up and gave him the most beautiful smile."

With that smile in their minds' eyes, Natalie and Ian wrenched themselves away and returned to the UK, exhausted but exhilarated. They couldn't get the orphanage out of their minds and simply couldn't return to life as it had been before. Nor did they want to.

The idea of adopting one of the South African children came to them, but initially they hesitated, because such adoptions seemed to be the preserve of super-rich celebrities like Madonna or Brad Pitt and Angelina Jolie – not a teacher and window cleaner from Yorkshire who both worked part-time in order to juggle childcare.

"We're not the stereotypical couple attempting inter-country adoption, in that they tend to be older, too, and they often can't have children of their own. We had my children, and hadn't even started trying for a baby of our own," says Natalie, who's now 34.

"And although we knew that such adoptions could be expensive, at the start of it all we had no idea how much legal red tape, paperwork and money were really involved.

"It was very important to us that Megan and Tristan were happy with the idea of us trying to help a South African child, and they were excited from the beginning. I researched international adoption and found that it was possible to adopt from practically anywhere, apart from South Africa, which had not fully signed up to the Hague Convention on protection of children and co-operation on inter-country adoption. But still I tried to find a way, coming up against many brick walls. "

Eventually, they were contacted by a female lawyer in South Africa who offered to help them, and 14 months later Ian, Natalie and the children went back to Durban to finalise legal proceedings.

During the lengthy process of assessments by social workers, which had involved both their families and many friends being interviewed about their suitability to adopt, and legal protocols which altogether cost them £17,000, little Star was becoming more and more poorly.

Her father was alive, but his family apparently did not want to bring up an HIV child. Her mother, who also had to sign away her right to the little girl, was very ill (presumed to be from an AIDS-related illness), and died just before Star left South Africa.

Just as the last legal hurdle was about to be crossed, the story of Madonna and Guy Ritchie's adoption of David Banda from an orphanage in Malawi hit the headlines, which meant the Westwells' adoption proceedings suffered a setback while the judge waited to consider the effects of the international media backlash. "The negative press Madonna got definitely didn't do us any favours," says
Natalie. "Everything stopped at a crucial moment, overturning a court order. But things calmed down and we were allowed to go ahead. Finally, Star was handed to us and we were free to get her a passport and leave."

Natalie and Ian are all too aware that what they have done is seen as controversial by some. "Star was three when we went back to get her, and her health had deteriorated dramatically. When we finally got her back here and a hospital in Sheffield agreed to look after her, we were told she was only two per cent away from full-blown AIDS. She would certainly have died if we had left her in South Africa.

"She has also brought a new meaning to our lives, and we would like to help other children in South Africa by opening our own orphanage there one day."

Fairytale endings are a myth, of course, although the Westwells feel happy and enriched by having adopted Star, and certainly have no regrets. The prognosis for their daughter is a long healthy life, so long as she takes her medicine and is monitored regularly by doctors. She is a picture of happiness and health and loves school.

The older children adore their little sister, the family talks all the time about Africa, of how Natalie and Ian met Star and the trip they all took to bring her to England. They plan to take her back to meet her family there in a few years' time, and, in the meantime, Natalie and Ian are also founding a charity to fund raise for the Makaputu Children's Village.

It wasn't until they brought a South African child with HIV into their family that the Westwells appreciated how patchy public understanding of HIV/AIDS is in the UK.

"We were faced with fear and prejudice," says Natalie. "There are still people who don't understand that there is no risk of cross-infection through their children playing with Star or eating at the same table. Star is oblivious to those kind of feelings, but we made a conscious decision to educate people, printing leaflets for adults and children, for schools and playgroups. People just fear the unknown, but we have to help them to understand so that we can do our bit to make the world
a better place for everyone with HIV."

Natalie says she has always believed in fate, and even more so now. "I believe that of all the places and orphanages we could have gone to, we were destined to go to that one and meet her. There's a reason that's bigger than us, and we were taken there to help not just her but others, too."