Edits were never mentioned to me, so I assume that the work was either left as is or the edits were small enough that she did them herself. I can't think that this was pre-edit, given that the book is supposed to come out March 31.
I would personally find not having edits by now for a book due out March 31st more troublesome than not having the contract mailed back.
As its a flash fiction piece, I wouldn't think there'd be much (if any) edits needed though. A polished 500 word (or thereabouts) piece submitted to an anthology call shouldn't require much in the way of edits, honestly.