So a full week after the blood sample was taken - I am not kidding - it now is revealed that mono is in fact being had, in addition to having previously been had, which I strongly suspected.
When we look back, it appears that F must have had it for quite some time, b/c she's been battling fatigue and headache and so forth for a while.
Think she's turned the corner, though. We're going to go shopping in a moment so we can gauge how much strength she actually has right now. There's the possibility of her returning to work on Monday, for a half-day at least.
Mrs. Who told me not to have any more crises.