The story of how two relatives of Jackie Kennedy Onassis finished up living in eccentric squalor in an abandoned mansion in upstate New York has had three bursts of American cultural publicity. The documentary Grey Gardens was a cult hit in 1975, becoming the inspiration for a hit 2006 Broadway musical, which was nominated for 10 Tony Awards and won three, inspiring in turn a 2011 TV drama.The fact that neither of the films made much impact in Britain – and it has taken a decade for the musical to have its British premiere – suggests that the material is perceived as being of mainly American interest, although, curiously, we have our own rough historical equivalent in Nerissa and Katherine Bowes-Lyon, nieces of the Queen Mother and cousins of the Queen, who were dispatched to