Thewlis joined
ITV Tyne Tees in 1987 as a presenter and producer, until 2008. She joined the
BBC in 2009, in which she has been a sports reporter alongside presenting the regional news programme
BBC Look North (North East and Cumbria) ever since. Thewlis has also presented various other programmes such as 'North East Tonight Election Special', 'Summer Sunday', 'A Current Affair', and 'The Football Show'. In 2011, Thewlis hosted a gala dinner to celebrate rugby player
Micky Ward's 13-year career. In 2015, Thewlis was part of the judging panel for students at
Northumbria University's Business School. In 2020, Thewlis presented an award at the North East Royal Television Society Awards. In 2023, Thewlis took part in a national journalists strike outside
BBC Newcastle as cuts were set to take place across local services. ==Charity work==