Breaking Dawn: How come Kate's electric charge thing doesn't work on Bella?

Thats a good question. If you really think about it, it's also a mind trick. So it doesn't Phase Bella when Kate is trying it on her.I don't know how the Charge is a mind thing but if you think about it, it works on every other vamp who doesn't have a shield. So its gotta be a mind thing. Get it? ;] i hope so.. i kinda confused my self.