Various members of the family have put together a family tree. Looking specifically at the descendants of my great-grandparents, it is quite startling. My ggps had twelve children surviving into adulthood. The information suggests that six of these twelve produced 46 grandchildren between 1947 and 1977 (I am eleventh youngest), and so far at least 44 great-grandchildren, from 1979 to 2003. Of those 44 ggc, 16 are descendants of my grandparents (who also had 16 grandchildren) and 19 from my great aunt who emigrated to the US (who had 11 grandchildren).
If everyone had uniformly produced 2 children, there would be 48 in my generation, and 96 in the next - although that still has plenty of scope for expansion, and, with more than a dozen of them now adults, I would expect a further generation in the not too distant future.
My great-great-great grandmother was an Unwed Mother, the daughter of a Dr Murray. She gave birth to my great-great grandmother in 1821 in Co Clare, Ireland. The family had to wait 170 years for another Unwed Mother!
Ooh, good heavens, said great-great-grandmother had my great-grandfather in 1867 - at the age of 46! My granny had my youngest auntie at the age of 43, in 1936. Two aunts had children at 40 and 42, in the 60s, and my mother (no blood relation to all that lot) had my brother at just under 40 in the 70s.
Declining fertility at my age, 36? I don't think so - I have another ten years yet!
This is of course, only a quarter of my family, although the other three quarters are less extensive.
