Proper Title 

Does anyone know if she is properly Raine de Chambrun or Raine Spencer, ie surname (not title)? Though she apparently tried to revert to her previous title, Raine, Countess Spencer, but cannot legally do that (though she certainly can use it socially, as has been done in the past by many titled divorcées/widows, including the Queen Mother's close friend Maureen Guinness, who continued to use and generally be called "Dowager Marchioness of Dufferin and Ava" despite two later marriages and divorces), did Raine legally retrieve her previous SURNAME, Spencer? Or is she still "de Chambrun", legally?