It was speedy, that was for sure, but it was just a pile of bones.  If it wanted to charge at her, she'd let it.  The Cleric spun her weapon above her head, and as the bone spider was about to reach her the cleric, she struck with it.  The spinning's momentum transformed into a horizontal strike that would cleave through leg and smash the "creature" across its "face".  Continuing through with the movement, she spun with the swing, hefting it up above her mid-spin and then swiftly swinging it down on the hopefully staggered spider.  She probably didn't need too many hits on the thing to dispose of it, if the vampire had to make a guess about it at all.