James Grant Forbes was born 22 October 1879 in Shanghai, China to Francis Blackwell Forbes (1839-1908) and Isabel Clark (c1846-1931) and died 24 April 1955 Paris, France of unspecified causes. He married Margaret Tyndal Winthrop (1880-1970) 28 November 1906 in 10 Walnut St, Boston, Massachusetts, United States.
Children
| Name | Birth | Death | Joined with |
| James Grant Forbes (1908- ) | |||
| Jock Forbes (aft1908) | |||
| Griselda M Forbes (aft1908) | |||
| Angela Elizabeth Forbes (aft1908) | |||
| Rosemary Isabel Forbes (1913-2002) | 27 October 1913 Paris, France | 14 November 2002 Manchester-by-the-Sea, Massachusetts, United States | Richard John Kerry (1915-2000) |
| Eileen G Forbes (aft1908) | |||
| Monica Ethel Forbes (aft1908) | |||
| Alistair Cameron Forbes (1918-) | |||
| Ian Archibald Forbes (1919-) | |||
| Iris Decima Forbes (aft1908) | |||
| Fiona Diedre Forbes (aft1908) | |||
Footnotes (including sources)
| ‡ General |