Sir William Ker of Cessford Peerage person ID=20695 (1544–1600) Parents Isabel Kerr Walter Ker of Cessford Children Margaret Ker Robert Ker, 1st Earl of Roxburghe Euphemia Ker Mary Kerr Elizabeth Ker Sir Mark Ker of Ormistoun Siblings Thomas Kerr Isobel Kerr Agnes Kerr Margaret Ker Sir Andrew Kerr of Caverton