Knappett was born in Bradford, West Yorkshire and grew up in Bingley before studying at the University of Manchester. She was a founder member of Lady Garden, a Sketch group who met in Manchester in 2005 and performed their first show at the 2008 Edinburgh Fringe Festival, returning in 2009 and 2010. During this period, the group toured throughout England, and performed at Sheffield, Manchester, Brighton, Comedy Festivals in 2008, were 2009 Hackney New Act & Laughing Horse Finalists, and won an Argus Angel for their show in the Brighton Fringe in May 2009.
