What we do know is, that she talked about it in an interview several weeks ago (during her short-trip to India, if I can trust my memory).
There she told the press that she hopes to be back in March. We assumed that she refers to her home-town tournament in Key Biscayne. So ... the last tournament before clay court season gets underway.
On a second note, we learned about a now confirmed exhibtion match scheduled for April during the week of Amelia Island's clay court event. (to take playce in Houston as far as I remember)