I'd be curious what her response would be if you replied with another question: ':)o you want to break me?'
I read that in Ivan Drago's voice. "Must you break me?" And then Soviet Anthem plays.
Ok, sorry.
I'm on a different page than the other folks given her actions. She was looking to tussle. If she actually cared what the answer was she would have had the conversation with you, not dropped it nor failed to revisit it. And, if you bring it back up not only have you taken the bait, but you'll have also shown her that she's able to monopolize your mind.
You know her best, but from where I sit she's looking to create drama, not have a meaningful conversation. If she does bring it up, offer a quick "nope" and move along. In the meantime, do things to course correct the behaviors you've engaged in to foster the drama. Granted, I'm speaking from my own experiences of having my wife test me with that type of question, but I've engaged and not, and not has been the right decision every time on those out of the blue one-offs.