Daughter of James Dallas of Cantray1 and Margaret Hamilton. She married the Rev. James Riddoch (d. 1778), Minister of the Episcopal Church in Aberdeen.
- 1James Dallas of Cantray died aged 30 at the Battle of Culloden in 1746. According to History of the Family of Dallas and their Connections and Descendants from the Twelfth Century (1921), he "probably took up arms at the end of 1745, and was one of the 700 or 800 gallant recruits who welcomed the Prince's return in January 1746, but there is no record of his occupation until the eventful day of Culloden, when he led his company against the forces of the Duke of Cumberland. [...] James Dallas is said to have been one of the first to fall, and he appears to have been buried on the field, though his body was afterwards disinterred in order to give it Christian burial. [...] In the Jacobite Memoirs occurs a list of questions addressed to the Rev. Mr. James Hay, a Jacobite minister in Inverness, one of which runs thus : ' Can you give me the name of that man whose body was taken up twenty days after being covered [...] without any corruption or smell in the least ? ' To which Mr. Hay made reply : ' The gentleman whose body was taken up after it was covered with a little earth was James Dallas of Cantray, a loyall, kind, brave young man, who rais'd his company at a great expense to serve his royall master."
Boswell first met and fell in love with Isabella in Inverness in 1761, when he travelled with his father on the northern judicial circuit. They met again in Aberdeen on August 22, 1773, during his and Johnson's tour of Scotland and the Hebrides, when they received an invitation for tea from Mrs Riddoch, as she then was. He later wrote of their meeting that "I was in a kind of uneasiness from thinking that I should see a great change upon her at the distance of twelve years. But I declare I thought she looked better in every respect, except that some of her fore-teeth were spoiled. She was the same lively, sensible, cheerful woman as ever."
Boswell referred to Isabella as his cousin, although they were very distantly related.