Michael Learned is a noted actress who played the mother,
Olivia, on the series
The Waltons ("Good night, Johnboy"). She is one famous example of the fact that
Michael has been used for both sexes.
http://www.imdb.com/name/nm0495229/bio
Of course I do recognize that usage is overwhelmingly male, still, it would not be without precedent to name a daughter
Michael.