Hello Fiona T,
From the information I have, William Carlile (began as a Silk Merchant and became a Master Bleacher) and Catherine Knox had a son, Thomas, who married Ann Sim. Thomas was a Spirit Merchant. From what I can see, they had at least three sons: Thomas, William and James. One son, Thomas Carlile, married Agnes Henderson and they had seven children. Their son, Robert, was my grandfather, my mother's father. I am aware of a Helen Polson McAusland marrying Thomas's brother, James.
I have been trying to connect my Carlile line with the well documented Paisley Carliles, but I can't get past William and Catherine. I thinks there may be clues in Houston.
Rosemarie L. is my mother's cousin's daughter and we have been briefly in contact. Clearly you and I are related too!