So, she arrived a couple of hours before Shabbat, to drop off a bag and pick up one of my sets of Shabbos keys. And then she left - her boyfriend was waiting for her in his car. She came back around midnight, when we were asleep, or pretty much there (her arrival woke me up but I didn't let her know.) She left around 8:30 AM and didn't show up again untiil a half hour ago, when she picked up her bag and dropped off the keys (and didn't wait for me to say good-night.)
Very odd indeed.
(Other oddity - we'd be asked to host someone for lunch - someone we've had over before. I emailed him to confirm, but he never emailed back. However, we asked two other guys to also come. G never showed up, either at shul or at the house. We had a nice lunch with T and Z, so all was well. But, still. Odd.)