I am researching the Dobbins of St. Mary's Bay as well.
I am researching Elizabeth Dobbin born about 1838, married to William Tobin. Her father's name was Bernard, born about 1855 - died 1936, and her mothers name was Ellen?. I believe Bernards father was a Patrick Dobbin, but not definitely sure about that. I am also hoping to find info on the Tobin family as well. Elizabeth and William's daughter Mary Ann Tobin married John Leander Judson McKenna, and settled in Queens County, Nova Scotia. Any help you can give me would be appreciated. I in turn will keep an eye out for your relatives. Good chance they are related.