Mary might not be the first name under which I "know" her or have her listed in my records. It could be that I have information on her in my files before her 1865 marriage, but that it is under a different first name.
One of my unstated assumptions about Mary Rampley was that her first name was "correct" on the marriage--or that it was the name she went by before her marriage.
This is turning into another good example of why writing is good for your genealogy research.