Pamela E. Ferris (born 11 May 1948) is a Welsh actress. She starred on television as Ma Larkin in The Darling Buds of May, and as Laura Thyme in Rosemary & Thyme, and has played parts in family films based on works by English authors, such as Miss Trunchbull in Matilda and as Aunt Marge in Harry Potter and the Prisoner of Azkaban, and most recently as Sister Evangelina in Call the Midwife.