Tatty Bullard had only been 18 for six days when she took to the capital's streets to raise money for a breast cancer charity which is supporting her ill mother.

The Oundle School pupil, who is now busy studying for her A-levels, completed the course in a time of four hours and 44 minutes.

And even more impressive is the fact she has raised a staggering £120,000 for Breast Cancer Haven – a charity offering alternative therapies to coincide with conventional cancer treatment.

Tatty wanted to raise lots of money for the charity which has helped her mum so much over the years.

She said: "The charity is really grateful and hopefully it will make a difference to a lot of women going through breast cancer.

"The day itself was a real experience – the atmosphere was incredible due to the huge numbers of supporters.

"The cheering and encouragement made such a difference and really helped me to keep going, particularly between 18 and 24 miles where the streets were packed with people helping us through the toughest part."

Tatty's proud parents, who live near Bury St Edmunds, were among a host of supporters cheering her on as she crossed the finishing line.

Oundle School's headteacher Charles Bush said: "This is a very special achievement for a remarkable girl."

The huge total of £120,000 included donations from her dad's business contacts as well as hundreds of friends, relatives and teachers.

In preparation for the gruelling challenge, Tatty had to juggle long training runs five days a week with her A-level studies in French, biology and psychology.

Tatty, who plans to take a gap year before studying languages at university, also completed the Reading half-marathon earlier this year.

Paul Arengo-Jones, chief executive of Breast Cancer Haven, which was set up in 1997, said: "We are absolutely thrilled with Tatty's donation. It really is a huge achievement to have not only completed the marathon but to have raised such an extraordinary amount for the charity."

For more information on the charity, visit www.breastcancerhaven.org.uk