Read our Privacy noticeNatalie Cassidy, known for her role as Sonia Fowler in EastEnders, says it was “freeing” to leave the soap earlier this year. Windsor played matriarch Peggy Mitchell in the soap and died in 2020. She said she decided to leave EastEnders after turning 40. “I think you know who you are, you know who your friends are, and where you are in life. “EastEnders is a brilliant job, but when you’re there, you’re chained.