Thanks, everyone, for your information regarding my inquiry. I already know about Stewart and Sarah in Canada. I have copies of all their documents: immigration (1877 both on the same ship but not listed consecutively), children's births and deaths, censuses etc. I have been to their grave sites in Vancouver. I know that Sarah's mother's maiden name is incorrect on her death record. It should be Catherine Gawley, but her death informant likely did not know that detail. I have come across many mistakes like that in all aspects of my searching in various countries.
I am in contact with cousins from both the Hull and Thompson families here in British Columbia. However, searching back in time has proven to be very difficult as records in Ireland are not often easy to find. I thought that perhaps Stewart might have had siblings whose descendants would have information. Nobody in my family has ever known the names of Stewart's parents nor the names of any siblings. Sarah's siblings also came to British Columbia, but I do not know of any relatives of Stewart having done the same.
Again, if anyone has information I would love to hear from you!