They used the term "least reinforcing scenario," which basically means trying to overlook it or just react calmly to it.
Interesting... .I would like to hear more. What does "react calmly" look like.
My suggestion would be to directly hand it back to her for action or perhaps directly ask about an emotion?
How do you feel about our family visiting... .or "the" family visit that is coming up? Goal here is to uncover emotion to validate. Not to "fix" her way of speaking.
For the tooth brush thing. Stay friendly and interested, then ask if she has a specific concern about tooth brushing. Listen to reply. If she declines to provide specifics... .directly ask if she has anxiety about the kids teeth.
If emotion is revealed... .validate it.
If you get blather... .stay friendly and let her know that you are open to discuss concerns or emotion about teeth brushing, she should let you know when she wants to discuss that.
In other words... .don't give her option for anything else and if she goes somewhere else, let her know you are open to continue the conversation on those topics. Don't debate whether or not she is staying on those topics.
Yes there is more energy expended this way than just ignoring it. I would also say that if you try this for month or two with no change from her side, I would change tactics or just start ignoring it.
Thoughts? You know her best... .
FF