In September 2013, Mitchell was re-appointed as the Scottish Conservative Justice Spokesperson[2] and sat on the parliament's Justice Committee and the Justice Sub-Committee on Policing. Mitchell is also a member of the Commonwealth Parliamentary Association (CPA) Scotland Branch Executive Committee. She also opposed the Act of parliament that legalised same-sex marriage in Scotland.
On 17 April 2020, Mitchell announced that she would be stepping down from Holyrood at the 2021 Scottish Parliament election. "By the end of this session in 2021 I will have had the privilege of representing my Central Scotland constituents for 18 years and I thank you all for your support," she said. "However at the end of last year I made the huge decision that, having achieved most of the things I set out to do, I would not seek re-election in 2021. In doing so I am re-assured that I leave my party's representation both at local government and parliamentary level in a much better place.[4]