It may be relevant to note that illegitimacy was exceptionally high in Banffshire, even in the context of Scotland, where illegitimacy was higher than in most parts of Europe. C T Smout, in his book A Century of the Scottish People, reports that in 1861-65 16.6% (one in six) births in Banffshire were illegitimate, compared with 4.2% (fewer than one in twenty) in Ross-shire. The stigma associated with illegitimacy in Banffshire was much less than in some other parts, and families in the census with a string of grandchildren are not unusual.
I have in my tree a Banffshire-born relative who had ten children by eight different fathers, only one of whom she actually married (and who was the father of three of the children). So your Helen or Ellen or Nellie Bain is not especially unusual in having several illegitimate children.
