She was one of the first Scottish women artists to make a career from painting, and according to Colin Russell "her importance remains in her struggle against gender prejudice".
[1] She was the granddaughter of the portraitist William Aikman, and was educated in Italy by the Scottish artists Gavin Hamilton and James Nevay, amongst others.
Having underestimated the travel and living costs involved, she was obliged to secure the financial support of a small syndicate of interested friends.
However, her business was not a success, Forbes being unable to produce works fast enough to meet the requirements of her clients, and she fell ill, eventually returning to Scotland.
In 1788 she was appointed Portrait Painter to the Society of Antiquaries in Edinburgh,[3] and she was able to make a living, albeit not a rich one, from painting and teaching art.