Biography
Married to James Dallas of Cantray (d. 1746), with whom she had at least two children, Isabella (1741-1792) and William (d. 1773-1774).
Life with Boswell
Margaret Hamilton was likely a distant relation of James Boswell's, probably sharing a common ancestor in Sir James Hamilton, 1st of Dalzell.
On August 23, 1773, in Aberdeen, Boswell went to see her, together with Mrs Isabella Riddoch (née Dallas, her daughter) and Prof. Thomas Gordon. Boswell did not write anything about their meeting, remarking only that he had not seen her since he was a mere child.