Firstly, she is a character who, when she decides she is going to do something, is totally committed to that action, whatever the consequences.
I think as well we can say that Lady Macbeth is resourceful and is not afraid of getting her hands dirty. She is a starter-finisher, to use the paralance of modern business speak. She will see her plan come to fruition even if she has to get involved herself.
Lastly, she is able to present a face that bears no indication of what is going on inside of her, which is always a useful ability to possess.
