LONDON ? Kate Middleton is turning website editor for a day, to help raise awareness of the stigma attached to mental health issues. The Duchess of Cambridge is guest editing the UK edition of the Huffington Post on Wednesday, but reporters won't spot her around the newsroom as she's running the show from her London residence in Kensington Palace. She led a morning editorial meeting with the website's editor at 10 a.m. and has commissioned stories from a variety of writers around mental health in children.