Personally I think you SHOULD chose an awkward time. Make that your thing, choosing an awkward time to iterate/reiterate your new mantra (well except when the kids are around). It might make her "do you" just to get you to shut up in the middle of the restaurant, or at the PTA meeting, how about church (well maybe that's going a little too far).
I don't think there is anything wrong in throwing her off balance. It will cause a shift in her thinking by breaking your pattern of certainty, and causing her to start having to "read" you. I can't see that as all bad. Anyway, if its uncomfortable for you, just think how she will feel the next time you pop it on her in front of ... hmmm let's see... well, there's Easter coming up....
