Lady Sarah McCorquodale, the elder sister of Princess Diana and aunt to Prince William and Prince Harry, was injured after a fall from a horse.

According to the Daily Mail, her brother, Charles Spencer, revealed that the accident occurred “last month” and that the 70-year-old Lady Sarah is still recovering in the hospital. Speaking on Giles Brandreth’s podcast Rosebud, Spencer humorously commented that his sister had been a “difficult patient”, noting that the chief doctor reportedly told her husband: “She really is a unique personality, isn’t she?”

“Sarah, who is almost ten years older than me, has always been strong-willed,” Spencer said, adding that “although she still rides, she had a very bad fall and was hospitalized for some time.”

No further details were given about the circumstances of the accident. Lady McCorquodale has remained close to her nephews since Princess Diana’s death in 1997. Last year, she was seen alongside Prince William at an official event.