Did my grandparents know their second cousins?

My father's father must have been aware of his second cousins, the Brodies of South Boston, New York. How so? Well I suspect he would not have been interested in the least, but when he visited Ireland in the 1950s, his cousin there (in the Garda) certainly had a notebook (which I saw at a distance) and in the address book were the Brodies. The weak link is we do not know for sure that the cousin mentioned the Boston cousins to my grandfather, but I think my grandfather would have divined their existence if not have ever known, heard or recalled the name.

My father's mother saw very little of her paternal side and I cannot imagine she knew any second cousins on that side. (Although one of her paternal cousins must have met the ones in Liverpool, the Draycotts and Hugheses, at a funeral in the 1930s.) Her mother emerged with a cousin briefly before we discounted him. I even had a note that there were no maternal cousins. There were, thanks to our out-of-wedlock origins which emerged in 2021. My grandmother (born 1905) actually has a second cousin, of the half-blood, still living, in Ontario, at the time of writing. Her niece took a DNA test.

My father's mother (continued). Can you tell she is my favourite line? She wrote about her family origins in hardly any depth at all. She knew her mother's second cousin Lilla, as this lady had married her uncle and attended my grandparents' own wedding in 1930. Her Grandmother's first cousin sent some postcards on this occasion as well. And in addition there was a postcard from another of her mother's second cousins (on a third line) sitting in the family trunk, which I found 100 years after it was sent.

My mother's father knew tonnes of his second cousins. There was Cyril (his mother's mother's side), Jean and her sister (his mother's father's side), the entire Harris clan (his father's mother's side) but especially the chicken farmer's wife. Ironically one of the last of his second cousins was Miss Hebbard (born 1928), however this lady was the granddaughter of great-aunt Mrs Mary Hebbard, and we never knew any of her family. They did not leave nearby. There was a note on the family tree she had 'married Mr Hubbard of Morriston' which was almost true. My grandfather had no real idea how the cousins all connected being the baby of the family.

My mother's mother. Funnily enough, although this is the line I worked first being the easiest, I really think the answer here has to be no. (Her eldest brother, my great-uncle - a comfortable networker with motive and opportunity - knew a good deal of them, but I am confident they were not discussed.)

So the answer is: yes if he wanted to (but not interested); not really (but mother's second cousins = yes), definitely and no.