The Setons – Margaret (Victoria Fairbrother) and Anthony (Michael Harbour) and their only child, 11-year-old daughter Kate (Joanna Joseph) – are a well-off middle-class family whose world is shattered when a scruffy 13-year-old girl named Rosie (Shelley Measures) turns up at the door of their Hampstead home with a poorly-written letter claiming that she is Kate’s long-lost sister, Emma, who was stolen as a baby from her pram outside a dress shop.
With her spiky hair and skimpy pink skirt, Rosie doesn’t look or dress like someone from Kate’s family.
She has been brought up on a street with pink nylons, silver bracelets and old clothes hanging out for sale, instead of lavender bushes and elderberry trees.
Is Rosie really Emma? That’s the mystery behind The Cuckoo Sister.
This BBC series was based on a novel by Vivien Alcock who died on 11 October 2003 in London.
Kate Seton Joanna Joseph Rosie Shelley Measures Margaret Seton
Victoria Fairbrother Anthony Seton
Michael Harbour Mrs Trapp
Toni Palmer Elizabeth Wait
Jo Kendall Uncle James
David Bacon Bettine
Jelena Budimir Harry Jenkin
Michael Egan
With her spiky hair and skimpy pink skirt, Rosie doesn’t look or dress like someone from Kate’s family.
