From the blog, Malabar Days, is found the story of Helen Somerville Fearson who was married at age 15 to Captain Donald Cameron. The Camerons were sent to India where [Major] Cameron (1754 - 1797) was killed in action. Her second husband was Thomas Hervey Baber; there's a film featuring Mr. and Mrs. Baber (described in detail in the Malabar Days blog post).
This letter  mentions Captain Donald Cameron. An earlier letter [24 August 1788] stated that the author "...formed an acquaintance about these Days with Captain Donald Cameron (Glendessary) belonging to the Bombay Establishment...".