It is difficult to determine the parentage of Marg. Caine, as there are a few Marg. Caines in K.M. at that time.
However I'd favour her parents as Hugh Caine and Ann Moore, married April 1696...this makes Margaret 21 when she marries Patrick Quiggan in 1719, and 44 when giving birth to her last child. Mary Knickel.....if she was born 10 years earlier, she'd be giving birth at 54.
Also she names her first son, John Quiggan, after Patrick Quiggan's father....her second son is Hugh Knickel....possibly named after her father???
Just a few thoughts...we'll never know for sure. Oh for the Tardis!