Looking for Parents of Mary Frances Mcinnes

I'm working on my family tree and I'm stumped as to the parents of my great-grandmother, Mary Frances McInnes. She was born in Nova Scotia on August 16, 1869 (or as late as 1872). She had three sisters -- Blanche (married last name was Coolidge), Alice (married last name was Ladd), and Isobel (married last name was Burgess). Mary Frances moved to Massachusetts and married John Marshall Cowen. I would like to find out who her parents were, where they came from and what they did.