In every case she foresaw someone's death, they died. Death WAS inevitable, just slightly delayed a time or two and the means sometimes changed, and Death ultimately explained (via a brief incarnation) to Dani that it was just doing it's job and she wasn't really helping by trying to fight it, just complicating things.
The one time she actually didn't foresee a death was Doug, and they handwaved that one away after the fact by suggesting that she had the power to see the probability of someone dying so seeing a possible death now DIDN'T mean it would happen, which was not how her power had ever worked before, or worked afterwards.