BBC One sitcom Big School (2013–2014), playing the main role of French teacher Sarah Postern in both series of the show. Tate later appeared as a nun alongside Walliams as Lou Todd in a Red Nose Day 2015 sketch, featuring Stephen Hawking in the Andy Pipkin role. In 2013, she accepted the role in the low-budget superhero comedy film SuperBob (2015) written by and starring Brett Goldstein as the title character, which led to a number of collaborations with Goldstein. Three episodes of her sitcom Catherine Tate's Nan, co-written with Goldstein, aired in January 2014 and December 2015 on BBC One. The role of Joanie Taylor earned her a nomination at the 2015 British Academy Television Awards for Best Female Comedy Performance. Tate calls Nan "the one [character] that's got the legs to carry on" and her favourite to play: "It's the one character I can look at on screen and not find myself in. It's a very good transformation. In lots of the others it's clear that it's me. I just enjoy playing that character mainly because you get the privilege of age where you can swear and people laugh. Old people swearing is funny." She reprised the role several times between 2009 and 2018 on Graham Norton, Michael McIntyre, Paul O'Grady and Alan Carr's television shows and performed Bonnie Tyler's song "Holding Out for a Hero" in character for Let's Sing and Dance for Comic Relief (2017). Tate portrayed both Eva Braun and Édith Piaf in the pilot episode of the Sky Arts sketch show Psychobitches (2012). In autumn 2014, she was cast as another real-life person in her first musical production, the Menier Chocolate Factory revival of Stephen Sondheim's Assassins (2014–2015). Her character was Sara Jane Moore, a woman who attempted to assassinate U.S. President Gerald Ford. She went on to play alongside Mark Gatiss and Judi Dench in The Vote, a James Graham play set in a fictitious London polling station, which was broadcast live on More4 on election night 2015. In spring 2016, Tate appeared as fashion designer Myrna in another musical comedy, Miss Atomic Bomb, at the St. James Theatre. Benjamin McDonald, writing in Gay Times, praised Tate's performance, saying she "proves she has the strong vocal ability to match her impeccable comic timing". The show itself received much poorer reviews, including a one-star review from The Stage.On New Year's Day 2016, Tate played