You could try this...
After three months have gone by, contact your local congressman and make a request for them to check on your wife's status (remember, this is a polite request to check the status only, you are not asking to intervene or expedite).
In most cases, after the congressman's office has made any inquiry, USCIS tends to show some updates on the website and you "may" see your replacement arrive a few weeks later.
This is by no means a guarantee that the congressman's inquiry will generate results. It is a hit or miss. I waited about 4 months for a replacement, and it only came after two inquiries were sent from the congressman's office.
Before you ask, do a google search on your congressman by typing who is the congressman of "your area" and just give their office a call. Ask to speak to someone who acts as a liasion to USCIS (most every office has one) and explain your situation. But I think they only assist if the case has been pending for at least 3 months, not less.
Good luck!