Even if Marvel had a director attached at this point, all she would be doing is waiting on the script to be finished like everybody else.
As unfair as it might be, Marvel has to be extra careful in choosing their first female director in order to best guarantee her success.
As Kroll was quick to point out, there is really no reason why Marvel should be in a hurry to make this decision.
Marvel could see this “burden” alleviated or increased depending on Wonder Woman‘s reception, but they know that making a great female centric superhero film led by a female director is important for everyone.