You won't
really know your or your wife's FICO scores until a lender runs your credit reports. You can get scores from the bureaus themselves (for an extra fee), but I find those scores fairly unreliable. I've seen big differences!
You can get a free copy of all three bureaus once a year. I would do that, make sure there's no negative information on your reports (especially your wife's). A consumer-obtained credit report will not cause you to lose any points as a lender-obtained report would. Also, make sure (your wife especially) doesn't have high revolving balances vs. credit limits. That will hurt a score dramatically. You can obtain these reports here:
www.annualcreditreport.com