Carden (or Garden) was also held by Walter Forrester of Torwood, and by his father Duncan and his son Mathew. The evidence for the Forrester/Livingston descent from King Robert III is in the second of Burke's articles, starting on p. 174. Burke cites The Acts of the Parliament of Scotland, 2:576-79, no. 24, quoting a statement that Agnes Graham, wife of Walter Forrester, was the sister of William, the third Lord Graham. This would make her the daughter of William Graham's mother Helen Douglas, wife of William, the second Lord Graham, who was married by 1460 (and who outlived her husband), with Agnes married by 1488, so Burke estimates 1468 as Agnes's year of birth, thus inferring that Agnes was Helen's daughter.
Helen appears as daughter of Sir William Douglas in a correction to Scots Peerage, 9:7, 11-12.