That would be my first thought too. Coverts have a special roundabout way of getting their messages across.

The other thought that comes to mind is if she's attempting a written smear campaign - trying to plant the false seeds that you're doing something inappropriate. Or maybe even hoping that you'll respond in a way she could use against you. They bait and fish a lot, as you probably well know

Totally agree with unaluna about habit and muscle memory too. It could represent a form of cptsd. In anxiety disorder, it's very common for someone to feel well healed, be subjected to an event or space where they were during the bad anxiety episodes, and have the horrible anxiety re triggered. It can even be completely subconscious to where the person doesn't know what the trigger was. I try to think of these types of triggers as passing shadows. They're there, they were possibly based on something at one time, but now they're really not much of anything. If you accept them for the passing shadows they are, they'll usually go on their way soon enough.