Published Thursday, 12 April 2012
The daughter of the British monarch's youngest son, Prince Edward, was riding her pony at her grandmother's Windsor Castle estate when she was involved in an accident.
She was taken to a nearby hospital and her arm was put in a cast.
A spokesperson for the royal family says: "She has been treated by doctors and is now resting at home."
Lady Louise's mother, Sophie, the Countess of Wessex, was involved in a riding accident almost exactly a year ago, just days before Prince William and Kate Middleton's lavish royal wedding, at which the eight-year-old was a bridesmaid.