Send a message to the person who requested a photo of the grave monument of Matthew Dagg with the following comment:
Elizabeth Margaret Stafford, then Snow, then Dagg was my 3rd great grandmother. My 3rd great grandfather was Thomas Snow who Elizabeth married in 1837. She then married Matthew Dagg in 1840. We do not know what happened to Thomas Snow, who was a mariner. Elizabeth and Thomas Snow had a son in 1838, also called Thomas Snow. Many thanks in advance for your help.