Here in the South, it is generally considered acceptable to give female babies masculine last names as first names. This trend predates Madison by over a hundred years, and has the caveat that the name be a family name of some sort. This is the way names such as "Meredith," originally a last name, became popular.
I think one couple has taken this trend to an extreme, though, simply naming their daughter "Smith."
Now, I know this is supposed to be a generally acceptable thing here in the South, but people, let's be real about this. You just can't get more masculine than Smith. It doesn't conjure up images of frilly lace and lipstick, or even baby dolls and ponies. It conjures up images of big, hairy, sweaty men working hard, nasty jobs. This is maybe not the imagery you want associated with your baby's name, no matter how cute you thought it might be, or how personal it is to your family.
I just hope there is a good family reason for this name, and that it's not a product of someone who was simply looking for another way to use a last name as a first name in some misguided attempt to be original. Originality is for writing, painting, decorating, and other forms of art. Originality is not for hanging a moniker on your child that will affect her every day for the rest of her life, or at least until she can legally change it.