I don't know who wants to hear this but it satisfies me talking about it so here we go.
Prue: Telekinesis/Astral Projection
As the older sister Prue has the strongest power and most effective during battle. People always wonder why her two powers are connected. Seeing as to how Astral Projection is moving the consciousness out of the body. I believe that her telekinesis expanded from moving things with her mind to being able to as well move her own consciousness out of her body and project it someplace else. Straight forward and easy right?
I'm not exactly sure as to why Piper is to get these powers but I believe it is probably how she is the middle sister and always gets caught up with her sisters that she just sometimes needs a break from them, to "freeze" them. Even though she can't freeze her sister or any good witch, it is just how i think her power is linked to her more than phoebe or prue.
Phoebe was always seen as the weakest and useless sister by demons and warlocks because of her passive power at first. I've heard people are confused as to why Phoebe got the levitation power when her powers are more emotion and mentally based. I think it is as to how her premonitions where very mentally based so it evolved to an active power of levitation because they both require concentration and lots of mental ability to be able to levitate in the air, you know? And then her Empathic powers came from her premonitions. Phoebe sometimes said how she could feel what she saw in her visions. So her power advanced to being able to feel other in real life as well.
Paige:Telekinetic Orbing, Orbing
Ok so there is not much to say about paige's powers because there isn't much to focus on. So i will not even talk about paige, not because shes not important but because her powers are all straight foward and easy to understand.