Royals came to my rescue

I had never considered Diana as a future princess; she was just a sweet lady who came to my house a few times - until the day she asked me to be her bridesmaid. I was only 10, and all the other girls were members of the aristocracy. Later, when I was sent to boarding school in East Sussex, I was very unhappy, but Diana kept my spirits up by sending me cards and letters.

It was Prince Charles's turn to help me earlier this year when I was, once again, going through a difficult time. At Christmas, my mother, Judy, was diagnosed with breast cancer. She is only 62.

I decided, with my friend Tanya Waters, whose mother also had breast cancer, to do something positive. We planned to raise money for Breast Cancer Care by doing a 22-day, 400km hazardous trip across the Namibian desert on horseback. One of the first people I wrote to for sponsorship was Prince Charles.

Although I haven't kept in contact with the royals I was amazed at how much interest Charles took in my adventure. He sent my mum a huge bunch of flowers, which really cheered her up, and agreed to sponsor me.

My father, Nicholas Gaselee, is a racehorse trainer based in Lambourn, Berkshire, where I grew up. During the time Charles was dating Diana, my father was training him as a jump jockey and they became friends. While the men were out riding, Diana used to come to the house. We got on really well, she was very sweet and lovely, and good at making friends with us children. However, I never expected her to ask me to be her bridesmaid.

I remember we were walking around a racecourse together when she just came out with it. I think I asked if I was going to be on television. Of course, at that age, I had no idea of the magnitude of the event. It was so exciting going to all the fittings - we all had to take turns at the atelier of David and Elizabeth Emanuel, and once Diana took me shopping in Bond Street. [The dress she wore is now in the Museum at Althorp, Diana's family home.]

My memory of the actual day is hazy, perhaps because I was so young, but I recall it was really hot and there were thousands of people everywhere.

My early appearance in the public eye, however, and my involvement with the late Princess has had its bad points. I don't want to just be remembered as her bridesmaid. The worst, during my teens, was when a reporter who said he was from a German magazine rang to ask if I would talk about Diana, and asked what I was up to now. It seemed harmless. He asked me what was the most frightening thing that ever happened to me.

I told him that I had taken a small overdose of painkillers - too many for a headache, not enough to do any lasting damage. Two days later, in September 1991, it was in a tabloid: "My suicide agony by Di's bridesmaid."

It's been something I have never been able to get away from. He twisted all my words. It was awful, really humiliating and mortifying. I didn't mean to take too many painkillers and I definitely was not trying to kill myself.

I had spent too much on my credit card - I just wanted some attention. But it really shocked me, especially when a doctor told me I could have done some lasting damage. What can I say? I was young and stupid and it was an accident. It just got blown out of all proportion.

Charles wasn't the only one to come to our aid; we wrote 700 letters asking for money. Tanya and I thought we would only raise a few thousand pounds, but the total was £37,000. We flew to Namibia on 10 May. I am quite nervous around horses - I'd had a bad fall when I was 16 and I am also allergic to them. However, four legs over 400km sounded a lot better than two. Our starting point was the famous Duwisib Castle on the edge of the Namib desert.

In 1909 a German baron, Henrich von Wolf, had brought more than 300 horses from Germany, but had been forced to set them free after they ran out of food. They adapted to desert life and 124 of their descendants now roam the desert. Our guide, Bettina, was an 18-year-old daughter of German settlers.

The first seven days were spent crossing 270km of beautiful farmland to a town called Aus. The horses were barely manageable - if one gallops, they all gallop.

One day, Bettina just sped off and our horses followed. Tanya and I had to desperately hang on, laughing hysterically. We rode between six and eight hours a day, stopping only for water breaks, and hardly saw anyone else.

Bettina's father drove ahead of us in a back-up vehicle, leaving jerry cans of water along the route and carrying our equipment. We would meet and set up camp before sunset. Our beds were sleeping bags under the stars and at times meals were little more than a packet of peanuts and rice cakes.

I was worried about snakes getting into our sleeping bags and had been told that hyenas would come and drag us off in the middle of the night. Tanya would fall asleep easily, but I would lie awake worrying. On day eight we finally saw about 80 of the wild horses - it was a spectacular sight, with their dreadlocked manes and tails dragging on the ground.

The terrain was often hard going for the horses, especially through the dunes where they would be up to their knees in sand. It would have been a disaster if one of the horses had broken a leg. And it was baking hot. The most frightening moment was when a group of young local men, who had seen our campfire from 50 miles away, drove up to investigate.

They didn't come and say hello - they just drove backwards and forwards, shouting and jeering. We were terrified but eventually they left us alone.

Then on day 13, the group was hit by a sandstorm - the horses had to wear masks and we sheltered behind rocks; I couldn't see further than my outstretched hand.

We only got back late on Sunday night, and by Monday morning I was at my desk in Kensington, where I work as a PA. It was an unforgettable experience and it's made me appreciate life more. Preparing for the trip got us through the dark month when my mother had to have a mastectomy.

Our parents were really proud of us. and I am planning my next trip already - next time we want to do the Sahara.

Breast Cancer Care: 0808 800 6000; www.breastcancercare.org.uk.