Sorry Wiggy,
I did research this some time ago, but only got to about where you are now, less the bit about Thomas Amos. (now that would have been a scandal back in those days if it was known).
As I said, I am only a distant relly, this by virtue of my great grandmother marrying Henry DUCKETT and her daughter Emma, my grandmother, married George POOLE, my grandfather, and Augustus STIEGLITZ, Ann's son, married Henry DUCKETT's sister Sarah, thus forming the distant link.
I will now keep an eye out for any clues of Catherine's journey but sorry I cant be of more help.
Regards, Aussie Bob