One possibility is that the old woman is near death. If the hospital cannot do much for you, many choose to go home to die (example, Paul Newman).
I despise Obama, but it is entirely possible his grandmother (who was much more a mother to him than his mother was) has gone home to die.
Argument against? He isn’t leaving for a couple of days...if someone is about to die, you don’t wait for 3 days.
Someone is going die, politically...