A case in point, is the birth place Catherine Reddie is giving in later censuses. We had her in 1861 showing her birth place as Newburgh. 1871 and 1881 she is showing as Brechin. From 1881:
John Laing 45
Catherine Laing 48, factory worker b. Brechin
Margaret Laing 22
Elizabeth Laing 19
John Laing 14
Alexander Laing 10
James Laing 8
Address: 2 Wallace Lane, Brechin (Wallance Lane is also where we have Catherine Reddie for her 1861 entry).
Daughter Margaret's birth entry on the index for IGI, who we had in 1861 with Catherine, shows as: Margaret Laing or Riddie, daughter of John Laing or Catherine Riddie b. 4 March 1859 in Brechin, Angus.
Monica