Hello Jeanne, I have no tie in with the Wylams yet, but I do have a number of female Birketts' still without married names. Could be one of these, but you have not given me her christian name! Let me know, and I will see if there are any possibles. 1851 is certainly about right for when my lot started to drift into the Newcastle and Durham area, from Haltwhistle. I have looked on the 1881 for the names you've given, and cannot see them. Had they died before then? I would have thought a Robert Birkett Wylam would be easy to find. This does of course depend on whether he gave the census enumerator his full name. Look forward to hearing from you.