Dawson was born as Marion Rowatt Bilsland in Houston, Renfrewshire, Scotland, on 19 January 1913 as the youngest of five children born to Alexander and Jane (née Alexander) Bilsland. She married Robert Dawson in 1941 and had two children named Jean and Allan. She has memories of both World Wars, “watching fires from the hill.”
Dawson was vaccinated for COVID-19 on her 108th birthday in 2021 at her local kirk, which was being used as a temporary vaccination site. Up until the pandemic, she had never missed a single Sunday service but still attended online services during the lockdowns.
On 22 October 2021, aged 108, Dawson became the oldest resident of Scotland following the death of 109-year-old Lois Fraser. The following year, she moved into a care home in Bridge of Weir. She celebrated her 110th birthday with lots of friends and family members, as well as the staff of her care home. A lifelong teetotaler, she never drank alcohol, preferring lemonade.