BORIS Johnson's family spreads from Downing Street to Celebrity Big Brother. With a pair of MPs and two reality stars among them-here's the lowdown on the Johnson clan.... 3 Boris, his daughter Lara Lettice and his mother Charlotte Johnson Wahl Credit: Getty-Contributor Who are Boris Johnson's siblings?... 3 Boris Johnson's family before the announcement of his victory in the London Mayoral election Credit: Getty Images-Getty Who are Boris Johnson's children?...