She exits the building.
She could try to sneak up on him. But he's barely more than a hundred feet away. The village is small. And when you move as fast as vampires can, that's really not much distance at all.
Vampires are fast creatures. They are stronger and swifter than humans. They are more graceful. They have faster reaction times.
She is strong, stronger than she should be. Not merely as strong as a vampire would typically be, for she was strong already before her transformation, and now those two sources of strength compound. And now she is graceful too. And together those mean that she is fast. Fast, fast, fast enough that when she launches herself off the ground, the vampire idly walking away from a burning building is going to find that she is moving faster than he can.
It's simple physics, really. She's much, much stronger than he is, and masses less to boot.
He's going to have time to react to her approach anyway. The village is small, and she is fast, but vampires are like that.
She will endeavour to hit him hard enough that this does not matter.