Is her credit history
exactly identical? I mean, did she not have any credit prior to your being married? If she had even one CC before you did, it would probably account for it.
When you and she check your reports does the CR give you two the same length of credit history?
Aside from that, seeing as how you've got the same accounts (and a payment on one would reflect on BOTH) I have no idea why that might be? Perhaps FICO's more gentlemanly to the ladies?

Have you guys printed out your CRs and checked them with fine-tooth comb? I think I would, if you haven't. You might not be jealous (though, I think I would be!! LOL!), but if you're missing a few points that you've EARNED, you ought to have'em!! And IMO, 20 points is enough that I'd spend a few hours doing it!!
Congrats on the high scores!! And a hearty welcome to the forums!!