As princes Harry and William prepare to unveil the statue of their mother at Kensington Palace, I can disclose that a headstone has finally been installed to mark the spot where Princess Diana’s larger-than-life stepmother, Raine Spencer, is buried seven miles away. The simple headstone, engraved with a gold coronet and the inscription ‘Countess Raine Spencer 1929-2016’, has just been placed in North Sheen Cemetery, South-West London, five years after her death. ‘She was elegant and unforgettable, but also very much a person who loved family,’ her daughter, Charlotte di Carcaci, tel...