Same family, same problem!
The correct John and Margaret Williams have a son, Robert, born at Holyhead in 1852. I have the census entries for Robert for 1881. He married Margaret Roberts (1853) of Llanfachraeth and in 1881 had 5 surviving children ... they lived at Jew St. Holyhead. I haven't been able to trace this family after this date. Robert was my great Grandfather and his son Owen, (1875), my Grandfather. I have the marriage cert for Owen ... they were married at St. Cybi's in 1901. It shows that Robert was deceased at this date. Further searches haven't produced anything from the 1891 census but I see a Robert Williams of the correct age, dying at Holyhead in 1891. I also see a marriage between Owen Hughes, (1857) of Bodedern and a Margaret Williams of the correct age. They were married in 1893 and shown at the wedding are Owen Williams, (my grandfather ?) and his sister Margaret?
This family, in the 1901 census, are at Bodedern with 3 children, but, once again, a niece and nephew named Williams are included.
What was going on in this family between the 1881 census, (their last child, another Robert, was born in 1881) and the positive info that Robert was deceased by 1901.
Any ideas out there?