Jade South during a showjumping competition.
Despite efforts by members of the riding group she was with, and two ambulance crews and a specialist doctor from the Great Western Ambulance Trust, she was pronounced dead at the scene.
Jade South lived at Linton, near Ross-on-Wye. She was a long-time member of the South Herefordshire and Ross Harriers branch of the Pony Club, which was running the day-long event at Pauntley Court, near Ledbury. About 20 other riders were at the event.
Douglas Clapham, owner of the Pauntley Court, told the Telegraph newspaper in Britain that he was in shock over the accident. "This is just a terrible tragedy. They had four very good instructors, but unfortunately just before they finished the girl was killed.
"They had been here before and there had never been a problem. It is absolutely tragic. We are bereft," he told the Telegraph.
Gloucestershire police said the coroner and health and safety executive had been informed of the accident.
Jade had been looking forward to a career with horses after completing work experience at an equine hospital. She was a pupil at John Kyrle High School, and lived with her parents Paul and Claire and 12-year-old brother, Robert, in Linton.
In a statement her parents saying her "love of horses outweighed everything else, even to the extent of choosing to miss a family holiday to attend Lea Show!"
"In 1999 Jade joined South Hereford and Ross Harriers Hunts branch of the Pony Club and weekends were never the same again. She attended many rallies and camp every year where she enjoyed helping younger members.
"She was honoured to have represented the branch at area level in show jumping, eventing and stable management.
"Last year she progressed to at affiliated level in show jumping. Numerous trophies have adorned the dresser over the years including the Robert Okell Memorial Plate at Harewood End Show.
"We would like to say a big thank you to the ever friendly people we have known throughout Jade's life, both children and adults. We have 15 years of memories of her as a wonderful daughter and sister to cherish and comfort us."