Actually, I am more struck by six's interpretation.

If it was passed to her, that means the mantle of sovereignty was passed to her by others, that she needed legitimizing either by the act of her predecessor dying for her, or by intermediaries.

If it simply passed to her, it is something that happens divinely and automatically, like the sun rising, because that is the natural way of things.

It looks rather strange without the "was" except for her. I would probably use a red pen and insert a "was" if I was checking a student's writing.
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We are what we repeatedly do - Aristotle