This is not a rules question or intended to be a discussion of the strength of her special melee ability. I am curious about that it represents in the fiction. What does she do that causes enemies to fall all around here in the distance, while she is fighting someone else in melee? I could see it as a storm of arrow if it was a ranged ability, but is clearly keyed to close combat. Do you we have any clue in the fiction for the game?
It can't be from her special experience and hate against undead, because the ability works against any enemy. Or is is simply a pure game effect without any thought giving to what it represents, which would be slightly disappointing? So far I haven't come up with a satisfying idea.