Well, in fairness, I don't think what happened to her was a molehill. I think it was wrong of her to say what she did, and what happened that day certainly devastated other lives in a way it did not devastate hers, and saying what she did was an exaggeration at best, so I can see why the saying seemed to fit. But "molehill" trivialises what did happen to her just a bit too much, I think.