As the British Royal Family continues to mourn the loss of their cousin, new details on how Rosie Roche died are revealed.

On July 14, the 20-year-old cousin of Prince William and Prince Harry was found dead in her Wiltshire home. The Wiltshire and Swindon coroner report she was killed by a “traumatic head injury,” according to the Daily Mail.

Roche’s mom, Pippa, and sister Agatha were the first to find her deceased in her home ahead of a planned trip. During the search, a firearm was allegedly found nearby her body inside the residence, according to The Sun.

“Rosie was getting ready to go away with friends and was packing her belongings at home,” Grant Davies, area coroner, said. “Upon checking the office in the house, Agatha found Rosie deceased, and she was slumped over a firearm with significant head trauma.”

The coroner added, police have ruled Rosie’s death as “non-suspicious and there was no third-party involvement.”

Rosie was the granddaughter of Princess Diana’s uncle, the 5th Baron Fermoy, Edmund Roche, who killed himself in 1984 after suffering from years of depression. He died at 45.

Rosie attended Durham University, where she was pursuing her English Literature degree. She leaves behind her parents, Pippa and Hugh, along with sisters Archie and Agatha.