My gut feeling is, don't worry...you and I seem to be on pretty similar timelines and the fact that there's a Decision Made should mean the COPR is on its way to your wife. When you applied for the extension to the Visitor Record (I did the same thing), did you specify the length of the period for which to extend it? I had one that was expiring at the end of August and so I specifically requsted 6 extra months (which I got...but I only got it in the mail about two weeks ago

).
Still, assuming it's a genuine form, it's their form to do with as they please, and if they choose to allot you an extension to December 2014 that's probably their prerogative. In all likelihood you won't be needing that form ever again anyway