Dame Diana Rigg portrayed Winifred Gillyflower in TV: The Crimson Horror. She is the real-life mother of Rachael Stirling who portrayed her character's daughter. She is also the first Dame Commander to appear in Doctor Who (and the first to have such an honorific included in her on-screen credit).
Diana Rigg is best known for playing Emma Peel in the Sydney Newman-created series The Avengers, and as Tracy in the James Bond film On Her Majesty's Secret Service, although she has a large resume of distinguished film, stage and TV roles. She was the second Game of Thrones actor to appear in Series 7 after Liam Cunningham.