The teenage daughter of financier Ben Goldsmith died when an "all-terrain type" vehicle she was driving overturned, an inquest heard.
Iris Goldsmith, 15, died on her family's farm near the village of North Brewham, Somerset, on 8 July.
Police are not treating her death as suspicious, the inquest in Taunton was told.
Her family have released pictures of their "angel" following her funeral on Wednesday.
Senior coroner Tony Williams adjourned the inquest, saying he had only limited information about the accident.
"I understand she was the driver of a left-hand drive all-terrain type vehicle when it turned over for reasons that are yet to be established, and as a result it is believed she suffered fatal injures," he said.
Pathologist Dr Edwin Cooper of Yeovil District Hospital confirmed the cause of death was "not currently ascertained" and a post-mortem report had yet to be compiled, he added.
A final inquest hearing is expected next year.
A private funeral for Iris was held at St Mary's Church in Barnes, south-west London, on Wednesday afternoon.
In a eulogy, Iris' mother, Kate Rothschild, said: "I can't possibly begin to explain the ocean of grief we find ourselves in or the feeling of being shattered into a thousand un-findable pieces.
"She was simply spectacular, her light was brighter than any I've ever known.
"Iris was life-giving and free and fun and wild, but she also worked harder than any girl I've ever known and she cared, she cared so much about living her best life.
"She had so many plans and dreams and ambitions and she was willing to put everything she had into reaching them."
Iris was the first child of Mr Goldsmith and his ex-wife Ms Rothschild.
Mr Goldsmith is the younger brother of Conservative MP Zac Goldsmith and Jemima Khan.