Apologize. It just gives her one less reason to be ticked at you.
I think you approach your marriage like this but I want to say it away. You're in a relationship and you want the relationship to work. This is more important than the "small stuff" that we all get caught up in. Your current "project" is to get her over this hump and climbing down from a joke just might help. You do this because you love this woman.
She's an attorney? Her profession is defining reality and convincing other people of it? She gets paid for warping some facts and discounting others. I hope she doesn't bring this into your relationship.
At all costs maintain your personal dignity and self-respect. After apologizing you might suggest that she lighten up a little. That despite your best efforts your frustration comes out one way or another and she's gotta admit that you're doing much better than before.
