Robert Ker, 1st Earl of Roxburghe Scottish nobleman (1569–1650) Parents Janet Douglas Sir William Ker of Cessford Children William Ker, Lord Ker Lady Isabella Ker Lady Jean Ker Lady Mary Ker Henry Ker, Lord Ker Siblings Euphemia Ker Mary Kerr Margaret Ker Sir Mark Ker of Ormistoun Elizabeth Ker Partners Margaret Maitland Lady Isabel Douglas Jean Ker, Countess of Roxburghe