It seems to me that if utilitarianism is to mean anything then the utility of the last two options should be the same - if we're allowed to assign utility values to the history of whether she was born and died, even though both possible paths result in the same world-state, then it would be equally valid to assign different utilities to different actions that people took even if they turned out the same, and e.g. virtue ethics would qualify as a particular kind of utilitarianism.

Whatever action I take right now, eventually the macroscopic state of the universe is going to look the same (heat death of the universe). Does this mean the utilitarian is committed to saying that all actions available to me are morally equivalent? I don't think so. Even though the (macroscopic) end state is the same, the way the universe gets there will differ, depending on my actions, and that matters from the perspective of preference utilitarianism.