Peaches Geldof, 24, has has more than 160,000 followers on Twitter and has previously written columns for the Daily Telegraph and Elle Girl and articles for the Guardian.
More top news
The boy matches no missing persons profile and police say they have yet to find any clues as to his identity.
Claire Lomas was greeted by cheering supporters after walking through the night to make it to the finish line.
The prime minister told MPs she was hopeful 'sufficient progress' would be made to move talks on to trade by December.