The girl's parents were also injured, with the father suffering life-threatening wounds.
The suspect, a 71-year-old Dutch pensioner, surrendered to police after the shooting.
The motive for the attack is not yet clear, but the two families had been involved in a long-standing dispute over a plot of land adjoining their properties.
The British family had lived in the hamlet for five years, and the Dutch neighbor was described as a private man.
The case has been handed to the public prosecutor in Brest.
LONDON DAILY ARCHIVE
British Girl, 11, Killed in France in Dispute Over Land
An 11-year-old British girl was shot dead in the garden of her home in Brittany, France, following a dispute between neighbors over land.
12 June 2023 · 22:49 UTC