lady macbeth's hand in murder

L. Macbeth wanted to be queen. She read Macbeth's letter about the witches' not so subtle suggestions and was all over the idea of becoming queen. We never really find out exactly why she wants to be queen. We can surmise that it wasn't to help the poor and needy. She just liked the idea of power and seeing that she felt that her husband had no testosterone, she thought she might be the power behind it all. So we have lines like,

"Glamis thou art, and Cawdor; and shalt be What thou art promised".....

"Come, you spirits

That tend on mortal thoughts, unsex me here,

And fill me from the crown to the toe top-full

Of direst cruelty. Make thick my blood."

Yes she even asks to be a man so she can have the courage to stab the hell out of Duncan. She really wants to be Queen!