I will actually back you up on this.
Sometimes, something really unpredictably nasty will happen healthwise that may be very unpredictable.
In this case she was photographed at the local Tube station 20 minutes before she was supposed to do a live radio interview. The previous night she had been caught completely unprepared in a live TV interview.
The story is that she has a undefined long-term illness. It does look as if she is being hidden from the press.