The use of the term Commissioned lends credence that they were official, however, I can find no evidence supporting this.

Note:

Although a few other Southern cities armed women briefly in response to local crises, LaGrange's women are considered unique, because their group would become a well-organized, disciplined, commissioned military company that would train regularly for almost three years.
http://www.civilwarwomenblog.com/2008/06/nancy-harts.html

"Both officers dismounting, Major Parkman then introduced us. "Colonel LaGrange, I have the pleasure of introducing you to a regularly commissioned officer of the Nancy Harts.’
http://planetanimals.com/logue/LaGrange.html