Is it ever mentioned in the books what happens if a wizard/witch dies after casting a spell with effects over a long period of time? In the movies - specifically the scene when Harry gets Slughorn drunk - we see that transfigurations are undone when the one who cast them dies (the fish turning back into a flower petal).

And that got me thinking: if Hermione died in the seventh book, after she'd placed the memory charm on her parents and went on the run, would they suddenly remember her? On the other hand, there's also the traps that Moody set in Grimmauld Place, which persisted long after his death. And I think that in the Battle of Hogwarts, the animated statues would have collapsed if McGonagall had died, since they required active control.