When your grandfather wrote that Martha Francey was from O'Morrow, Ireland, was it stated clearly whether O'Morrow was a place or a family? There is no place in Ireland (that I'm aware of...) called O'Morrow, however my grandmother's last name was O'Morrow, and they came from Ireland. I haven't yet been able to place where exactly from Ireland they originated though. I've only been able to trace it back to my grandmother's grandfather (Charles O'Morrow, and his 2 brothers, John and Lloyd). They were born in the mid to late 1800's. I know John O'Morrow ended up in Canada, but I don't know where in Canada.
It's just another possiblity. If the O'Morrow your grandfather refered to does end up being a family and not a place, please let me know, I'd be interested.