Originally trained at The London Hospital, Whitechapel, Michelle began her career working as a staff nurse in the Intensive Care Unit, then moved into Health Service Management. Michelle went on to hold a number of posts within finance before moving to South West Thames Regional Health Authority as the Deputy Regional Finance Training Manager.
In 1990 Michelle and her husband decided to move to the Scottish Borders in order to set up their manufacturing company and raise their six children, establishing their business in Walkerburn and settling near Selkirk.
After the move Michelle continued to work as a nurse while also completing an Honours degree at Heriot Watt University. She then returned to Health Service Management in 2000, latterly managing Acute Medicine in Edinburgh before moving in 2005 to head up an independent charity providing specialist drug and alcohol support to children, families and offenders.
In 2012 Michelle was elected to Scottish Borders Council, where she served as Leader of the Conservative Group. Michelle was then successfully-re-elected in March 2017 and resumed her position as leader at Newtown St Boswells.
In May 2017 Michelle became a list MSP for the South Scotland region, covering Midlothian South, Tweeddale, Lauderdale and East Lothian, while retaining her council seat. Michelle has since stood down from Scottish Borders Council to focus on her duties as an MSP. At the Holyrood Election in May 2021 Michelle will be running to become the constituency MSP for Midlothian South, Tweeddale and Lauderdale.
During Summer 2017 Michelle was appointed as the party's Spokesperson for Childcare and Early Years. During her first year in Holyrood, she sat on the Public Petitions Committee and was a substitute member of the Justice Committee.
In May 2018 Michelle was promoted to the Shadow Cabinet as Shadow Cabinet Secretary for Communities and Social Security. Following this announcement, Michelle left the Public Petitions Committee to take up a seat on the Social Security Committee.
Michelle stepped down from her portfolio in social security to become the convener of the Scottish Parliament's Economy, Energy and Fair Work Committee.
In August 2020 Michelle was promoted to the role of Shadow Minister for Trade, Investment and Innovation.
In November 2020 Michelle left the Scottish Conservative Party and in January 2021 became Leader of Reform UK Scotland.