<Li> Oscar Steer as Vincent David Green, the youngest of the Green children . </Li> <Li> Eros Vlahos as Cyril Sean Gray - the spoiled cousin of Norman, Megsie, and Vincent . He becomes kinder throughout the film and makes friends with Norman . </Li> <Li> Rosie Taylor - Ritson as Celia Rosa Gray - the other spoiled cousin of Norman, Megsie, and Vincent . </Li> <Li> Maggie Smith as Agatha Rose Doherty (née Brown), the owner of the shop at which Mrs. Green works . She is baby Aggie from the first film grown up . </Li>

Who plays celia in nanny mcphee and the big bang