as Diane, the teacher's assistant and long suffering girlfriend to primary antagonist gym teacher Gary Rothbauer (Justin Hartley) plus Christmas set romantic comedy Single All the Way (2021) as Ashleigh, young mother of two small children and a supportive sister to the lead Peter (Michael Urie). Television Her first television role was in the children's/family series Darcy's Wild Life (2004-06) as Kathi Giraldi. 2008 saw the release of two TV movies with her in. As Angie Bremlock in Never Cry Werewolf, wherein a werewolf moves in to terrorize a neighborhood, and True Confessions of a Hollywood Starlet, where she was Emily a girl who unwittingly befriends incognito teen celebrity Morgan Carter (Joanna "JoJo" Levesque). Incidentally True Confessions of a Hollywood Starlet also featured her future Todd and the Book of Pure Evil co-star Bill Turnbull in a small role. The same year she was part of the main cast of characters in House Party (2008), the desperate to please Mandy. Each episode focuses on a particular character, revealing the various plot developments to the audience as they are encountered by the episode's focal character. The show was re-released in 2021 by the production company Farpoint Distribution on their YouTube channel. 2009 saw a role in Being Erica, Season 2, Episode 19 "Shhh... Don't Tell" playing Fiona Watt, a student that's being mercilessly bullied and humiliated by other classmates. In 2010 she co-starred in the Canadian television horror/comedy series Todd and the Book of Pure Evil as science geek Hannah B. Williams who forms part of the team at Crowley High School that "fights evil with mixed results". The show was renewed for a second season, that aired in 2011, where she reprised her role as Hannah. Leishman shared a Gemini Award for "Best Ensemble Performance in a Comedy Program or Series" with her cast mates for their work on the show. In 2011 she voiced bossy popular girl Brandy Silver in the school set mystery animated series Detentionaire and also voiced the overly perky and thus aptly named Chipper in Grojband. She has appeared twice in long running detective series Murdoch Mysteries, as two different characters. First as Nancy Booth, a taken advantage of maid, in "Downstairs, Upstairs" and later as Sarah Harrison, who gets entwined in espionage between the US and Canada following the assassination of U.S. President William McKinley, in "The Spy Who Came Up to the Cold".