Thanks for the two messages. I did look at the Robert Brew will 19/7/1794 and didn't think it was the right one. He had a daughter Margaret by his first wife Esther Marteen/Mylchraine, but no Catherine, also because there was no mention of his new wife's children.
The Joney d/o William Corrin/Joney Clark looks promising and I will follow that up.
Your time and advice is much appreciated.