Actually it was started by her sister, Margaret, when they were young. Margaret couldn’t pronounce Elizabeth, so she called her Lilibet. It became the family pet name for her and Prince Philip began using it when they married. That said, it is a private family name and it seems tacky to flash it out like this. The British people, who commented n the Daily Mail article, are enraged.
I compleyely agree. I was appalled when I saw the name. It is presumptuous and tacky.