British pop star Lily Allen has a secret half brother who spent time in jail while his famous sister enjoyed a privileged upbringing. KEVIN MARSHALL was borne of a romance between actor/comedian Keith Allen and shop assistant SANDRA MARSHALL in 1982. Keith married film producer Alison Owen in 1984, who gave birth to Lily a year later. Before rising to fame last year (06), Lily visited her half-brother as he spent time in jail for car theft to bring him gifts and urging him to quit the life of crime. Kevin, 25, says, "I could tell she was upset to see me in a cell but when she walked in I was so happy. "She brought me a tracksuit and trainers. "She said she wanted us to be more of a family when I got out and that she didn't want to see me in places like this again."