This is more because of the fact that the show is base on the 3 sisters and not really because of Rose McGowan. It seems to me that their powers are link to the fact that they are 3 sisters and it's confirm when they travel back and forward in time. Like I've said I've lost interest after the third season, so I've no idea how the show creator bypass the logic of the first seasons. But, I will probably buy the 4 one just to know it.