Question: What character did Pam Ferris play in the film based on a J.K Rowling novel?

Context articles: Matilda (1996 film)
Within the Whirlwind
Clare Mackintosh
Pam Ferris
Maluuba
List of Call the Midwife episodes
Mark Estdale
Harry Potter and the Prisoner of Azkaban (film)
Barry Cunningham (publisher)
Christopher Little Literary Agency

Matilda is a 1996 American children's fantasy comedy film directed by Danny DeVito, who also produced with Michael Shamberg, Stacey Sher, and Lucy Dahl.
 It was written by Nicholas Kazan and Robin Swicord, based on Roald Dahl's novel of the same name.
 Mara Wilson, DeVito, Rhea Perlman, Embeth Davidtz, and Pam Ferris star.
 The film is about a young genius named Matilda, who uses telekinesis to deal with her parents, who do not value education, and Agatha Trunchbull, the oppressive principal of Crunchem Hall Elementary School.
Within the Whirlwind is a 2009 film directed by Marleen Gorris and based on the book by Eugenia Ginzburg.
 It stars Emily Watson and Pam Ferris.
 Watson has described the film as "the most stretching thing I’ve done as a mature actress."
Clare Mackintosh is a British author.
 A former policewoman, her debut novel "I Let You Go" was a Richard & Judy book club pick.
 It won Theakston's Old Peculier Crime Novel of the Year Award in 2016, beating J K Rowling writing as Robert Galbraith.
Pam Ferris (born 11 May 1948) is a Welsh character 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 British 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".
Maluuba is a Canadian artificial intelligence company conducting research in deep and reinforcement learning.
 The company vision is to solve fundamental problems in language understanding with a goal towards solving artificial general intelligence.
 This technology will allow machines to understand and answer questions about written documents, and have natural conversations with users.
 In late March 2016, the company made headlines by demonstrating a machine reading system capable of answering arbitrary questions about J.K Rowling’s "Harry Potter and the Philosopher’s Stone".
"Call the Midwife" is a British period drama television series based on the best-selling memoirs of former nurse Jennifer Worth, who died shortly before the first episode was broadcast.
 It is set in the late 1950s and early 1960s and for the first three series centred primarily on Jenny Lee (Jessica Raine), who, in the first episode, begins a new job as a midwife at a nursing convent in the deprived Poplar district of London.
 The programme's ensemble cast has also included Jenny Agutter, Pam Ferris, Judy Parfitt and Laura Main as nuns living at the convent, and Miranda Hart, Helen George, Bryony Hannah, Charlotte Ritchie and Emerald Fennell as other midwives.
 Vanessa Redgrave delivers framing voiceovers in the role of "mature Jenny", and continues to do so even after the younger version of the character was written out of the series.
Mark Estdale is a British voice director, sound engineer, voice actor, and casting director.
 In the 1980s he worked as a sound engineer for musicians such as The Box, UV PØP, and industrial band In The Nursery.
 He co-founded the electronic band Chains with Peter Hope, which in 1986 released a single on Native Records.
 In the 1990s Estdale began working on video games, and is well known in the industry for founding the voice production company Outsource Media in 1996.
 As casting and voice director he's worked on over five hundred video games since 1995, including titles such as "TimeSplitters 2", "J K Rowling's Book of Spells", "Clive Barker's Jericho" and "Wallace & Gromit's Grand Adventures".
Harry Potter and the Prisoner of Azkaban is a 2004 British-American fantasy film directed by Alfonso Cuarón and distributed by Warner Bros.
 Pictures.
 It is based on the novel of the same name by J. K. Rowling.
 The film, which is the third instalment in the "Harry Potter" film series, was written by Steve Kloves and produced by Chris Columbus (director of the first two instalments), David Heyman, and Mark Radcliffe.
 The story follows Harry Potter's third year at Hogwarts as he is informed that a prisoner named Sirius Black has escaped from Azkaban intending to kill him.
Barry Cunningham (born 19 December 1952) is a British publisher, who worked for various publishers including Penguin Books and Bloomsbury before setting up Chicken House publishing in 2000.
 He is most well known for signing J.K Rowling, and publishing "Harry Potter and the Philosopher’s Stone" in 1997.
The Christopher Little Literary Agency is a firm of literary agents based in London, UK.
 Its clients include Janet Gleeson and Darren Shan.
 Little also managed Harry Potter author J.K Rowling from 1996 until 2011 and has been credited with single-handedly managing Rowling's career and turning the "Potter" franchise into a multi-million pound industry.